Cannot access dependency injected inside strategy pattern implementation class

I am trying to implement the strategic pattern,the problem is that I could not access any dependency injected inside the strategy implmentation classes, so here is my code

Payment strategy interface

public interface PaymentStrategy {
    public void processPayment(double amount);
} 

Payment strategy interface implementation

@ApplicationScoped
public class CreditCardStrategy implements PaymentStrategy {

    @Inject
    @RestClient
    ApiExample apiExample

    public void processPayment(double amount) {
         apiExample.doSomething() **//NULL POINTER EXCEPTION**
        // Process credit card payment
    }
}

@ApplicationScoped
public class PayPalStrategy implements PaymentStrategy {

    @Inject
    Service service

    public void processPayment(double amount) {

         service.doSomething() **//NULL POINTER EXCEPTION**
        // Process PayPal payment
    }
}

Payment strategy factory

public class PaymentStrategyFactory {
    public PaymentStrategy getPaymentStrategy(String paymentMethod) {
        if (paymentMethod.equals("creditcard")) {
            return new CreditCardStrategy();
        } else if (paymentMethod.equals("paypal")) {
            return new PayPalStrategy();
        } else {
            throw new IllegalArgumentException("Invalid payment method: " + paymentMethod);
        }
    }
}

Main program method

String paymentMethod = "creditcard"; // Or "paypal"
PaymentStrategyFactory factory = new PaymentStrategyFactory();
PaymentStrategy paymentStrategy = factory.getPaymentStrategy(paymentMethod);
PaymentProcessor paymentProcessor = new PaymentProcessor(paymentStrategy);
paymentProcessor.processPayment(100.0); //NULL POINTER EXCEPTION CAUSED BY apiExample.doSomething()

To expand on the answer given in the comments, here's how you might get the bean from the context in spring. Here's a quarkus example of how you might do this.

it prints:

2023-03-18 10:08:57,311 INFO  [org.so.q75.Example] (Quarkus Main Thread) ApiExample processed!
2023-03-18 10:08:57,316 INFO  [org.so.q75.Example] (Quarkus Main Thread) CreditCardStrategy processed!
2023-03-18 10:08:57,317 INFO  [org.so.q75.Example] (Quarkus Main Thread) PaymentProcessor processed!

// src/main/org/so/q75775998/Example.java
package org.so.q75775998;

import io.quarkus.runtime.Quarkus;
import io.quarkus.runtime.QuarkusApplication;
import io.quarkus.runtime.annotations.QuarkusMain;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.inject.Instance;
import javax.inject.Inject;

@QuarkusMain
public class Example implements QuarkusApplication {
    private static final Logger log = LoggerFactory.getLogger(Example.class);

    @Inject
    PaymentProcessor paymentProcessor;

    public static void main(String[] args) {
        Quarkus.run(Example.class, args);
    }

    @Override
    public int run(String... args) throws Exception {
        paymentProcessor.processPayment(100.0);
        return 0;
    }

    @ApplicationScoped
    public static class PaymentProcessor {
        @Inject
        Instance<PaymentStrategy> paymentStrategies;

        void processPayment(double amount) {
            paymentStrategies.iterator().next().processPayment(amount);
            log.info("PaymentProcessor processed!");
        }
    }

    public interface PaymentStrategy {
        void processPayment(double amount);
    }

    @ApplicationScoped
    public static class CreditCardStrategy implements PaymentStrategy {
        @Inject
        ApiExample apiExample;

        public void processPayment(double amount) {
            apiExample.doSomething();
            log.info("CreditCardStrategy processed!");
        }
    }

    @ApplicationScoped
    public static class ApiExample {
        public void doSomething() {
            log.info("ApiExample processed!");
        }
    }

    @ApplicationScoped
    public static class PayPalStrategy implements PaymentStrategy {
        @Inject
        Service service;

        public void processPayment(double amount) {
            service.doSomething();
            log.info("PayPalStrategy processed!");
        }
    }

    @ApplicationScoped
    public static class Service {
        public void doSomething() {
            log.info("did something!");
        }
    }
}

// pom.xml (initialized from https://quarkus.io/guides/lifecycle)
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.acme</groupId>
  <artifactId>lifecycle-quickstart</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <properties>
    <compiler-plugin.version>3.10.1</compiler-plugin.version>
    <maven.compiler.release>17</maven.compiler.release>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <quarkus.platform.artifact-id>quarkus-bom</quarkus.platform.artifact-id>
    <quarkus.platform.group-id>io.quarkus.platform</quarkus.platform.group-id>
    <quarkus.platform.version>2.16.4.Final</quarkus.platform.version>
    <skipITs>true</skipITs>
    <surefire-plugin.version>3.0.0-M7</surefire-plugin.version>
  </properties>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>${quarkus.platform.group-id}</groupId>
        <artifactId>${quarkus.platform.artifact-id}</artifactId>
        <version>${quarkus.platform.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>io.quarkus</groupId>
      <artifactId>quarkus-arc</artifactId>
    </dependency>
    <dependency>
      <groupId>io.quarkus</groupId>
      <artifactId>quarkus-junit5</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <groupId>${quarkus.platform.group-id}</groupId>
        <artifactId>quarkus-maven-plugin</artifactId>
        <version>${quarkus.platform.version}</version>
        <extensions>true</extensions>
        <executions>
          <execution>
            <goals>
              <goal>build</goal>
              <goal>generate-code</goal>
              <goal>generate-code-tests</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>${compiler-plugin.version}</version>
        <configuration>
          <compilerArgs>
            <arg>-parameters</arg>
          </compilerArgs>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>${surefire-plugin.version}</version>
        <configuration>
          <systemPropertyVariables>
            <java.util.logging.manager>org.jboss.logmanager.LogManager</java.util.logging.manager>
            <maven.home>${maven.home}</maven.home>
          </systemPropertyVariables>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-failsafe-plugin</artifactId>
        <version>${surefire-plugin.version}</version>
        <executions>
          <execution>
            <goals>
              <goal>integration-test</goal>
              <goal>verify</goal>
            </goals>
            <configuration>
              <systemPropertyVariables>
                <native.image.path>${project.build.directory}/${project.build.finalName}-runner</native.image.path>
                <java.util.logging.manager>org.jboss.logmanager.LogManager</java.util.logging.manager>
                <maven.home>${maven.home}</maven.home>
              </systemPropertyVariables>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  <profiles>
    <profile>
      <id>native</id>
      <activation>
        <property>
          <name>native</name>
        </property>
      </activation>
      <properties>
        <skipITs>false</skipITs>
        <quarkus.package.type>native</quarkus.package.type>
      </properties>
    </profile>
  </profiles>
</project>