Reflector not injected to my custom guard in nestjs

I have created a guard in a separate module for checking feature flags as below

@Injectable()
export class FeatureFlagGuard implements CanActivate {
    constructor(
        private reflector: Reflector,
        private featureFlagService: FeatureFlagService
    ) {}

    async canActivate(context: ExecutionContext): Promise<boolean> {
        const featureKey = this.reflector.get<string>(
            FEATURE_FLAG_DECORATOR_KEY,
            context.getHandler()
        );

        if (!featureKey) {
            return true;
        }
        return await this.featureFlagService.isFeatureEnabled(featureKey);
    }
}

and here is my decorator

import { SetMetadata } from '@nestjs/common';

export const FEATURE_FLAG_DECORATOR_KEY = 'FEATURE_FLAG';
export const FeatureEnabled = (featureName: string) =>
    SetMetadata(FEATURE_FLAG_DECORATOR_KEY, featureName);

Then in appModule I provided the FeatureFlagGuard as below

    providers: [
        {
            provide: APP_GUARD,
            useClass: FeatureFlagGuard
        }
    ]

Then in my controller

    @FeatureEnabled('FEATURE1')
    @Get('/check-feature-flag')
    checkFeatureFlag() {
        return {
            date: new Date().toISOString()
        };
    }

When I run the code I get this error, since the reflector is injected as null into my service

[error] [ExceptionsHandler] Cannot read properties of undefined (reading 'get')

Not sure what I missed

Thanks to @jayMcDoniel to give me a clue

The issue was the FeatureFlagService was not exported from the module. When I exported it the issue is resolved