using jib for multiple project build

I have a multimodule project that I am trying to use gradle 7.5.1 and jib to build and deploy each service artifact to ECR.

I have a ~/.docker/config.json file

{
  "credsStore": "desktop"
}
{
        "credHelpers": {
                "public.ecr.aws": "ecr-login",
                "xxxxxxx.dkr.ecr.us-east-1.amazonaws.com": "ecr-login"
        }
}

and my AWS keys are in ~/.aws/credentials

Each of my modules has a settings.gradle that defines the rootProject.name to be the service (artifactId), as well as the plugin 'maven-publish'.

In my main project I have a build.gradle:

plugins {
    id 'java'
    id 'groovy'
    id 'com.google.cloud.tools.jib' version '3.3.0'
    id 'maven-publish'
} 
..
jib {
    from {
        image = 'azul/zulu-openjdk:17-jre'
    }
    to {
        image = 'xxxxxxx.dkr.ecr.us-east-1.amazonaws.com/${rootProject.name}'
        // I have also tried image = 'xxxxxxx.dkr.ecr.us-east-1.amazonaws.com/${artifactId}'
    }
}

When I try to build them via gradle jib I get the following error:

> Task :jib FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':jib'.
> Invalid image reference xxxxxxx.dkr.ecr.us-east-1.amazonaws.com/${rootProject.name}, perhaps you should check that the reference is formatted correctly according to https://docs.docker.com/engine/reference/commandline/tag/#extended-description
  For example, slash-separated name components cannot have uppercase letters

The stacktrace also mentioned the invalid reference.

I am following several tutorials and the Google jib documentation, but I do not see what I am doing wrong - anyone else know?

Use double quotes instead of single quotes to make Gradle expand properties.