right, so let me answer my own question

theres miscommunication about the workspace id, it seems that the workspace on both environtment (release and test) have the same workspace id, BUT to use the test env, you can't manually add the _DEBUG behind the workspace id, it only applicable for API access for manual hit

so if you want to use the TEST env, you need to build the app in debug mode, if you build it in release mode, it'll use the MoEngage live env