Google storage bucket iam member resource missing project argument

Hello folks,
I am trying to apply google_storage_bucket_iam_member resource to serviceAccount on project A to read from a bucket on project B.
Now, from the docs, the argument project is listed (although optional), but when I perform a plan, it says:

An argument named "project" is not expected here

Theoretically, I should be able to specify where this bucket is located by adding the argument project to the resource definition, but apparently this is not working.

Any idea?

I’m using tf 0.12 with provider_version =~3.1

Thank you