@Aysun: In regards to the email associated with this Google Groups thread, I believe the only difference would be that you'll get updates of the posts happening here on your email that is registered with this group. In your case that would be your personal one if that is the one linked to this thread. As for the your Google Cloud Project, you would not be able to access it without explicitly granting access/roles to the email you want to use.
@Gaurav: I believe my original answer regarding
Google Cloud Platform was not what you were inquiring about. I was under the impression that you had a pre-existing GCP project that you could not access despite getting the "owner" role as discussed
here. However, as you mentioned you do not use the developer console and do not have any projects in there, you can disregard my initial suggestion.
As for your original issue for
My Business API, I was able to find the official support page for this product
here. There are a few support options listed there. You may consult the appropriate support team there for your inquiry there.
I hope this helps!