2-user-access-key.ts

private static createUser(scope: cdk.Construct): iam.User {
    const name = 'User';

    return new iam.User(scope, name, {
        userName: name
    });
}

private static createAccessKey(
    scope: cdk.Construct,
    javascriptArtifactsS3User: iam.User
): iam.CfnAccessKey {
    const name = 'UserAccessKey'

    return  new iam.CfnAccessKey(scope, name, {
        userName: javascriptArtifactsS3User.userName
    });
}