Git repository at did not contain a project publishing the specified dependency

Hi! I’m using the Source Dependency feature detailed here: https://blog.gradle.org/introducing-source-dependencies

//settings.gradle

include ':codegen'
sourceControl {
    gitRepository("https://github.com/twof/swagger-codegen.git") {
        producesModule("io.swagger:swagger-codegen")
    }
}

//build.gradle

implementation("io.swagger:swagger-codegen") {
    version {
        branch = "AdditionalPropertiesFix"
    }
}

// assemble command output

Could not determine the dependencies of task ':codegen:compileJava'.
> Could not resolve all task dependencies for configuration ':codegen:compileClasspath'.
   > Git repository at https://github.com/swagger-api/swagger-codegen.git did not contain a project publishing the specified dependency.
     Required by:
         project :codegen

Any idea what’s going wrong here? I’m rather new to gradle, so apologies if I’ve broken conventions.