google scholar has not listed me as coauthor
It is a bit difficult to speak on behalf of Google here. The best idea is probably to contact them directly [1].

Before you do that, however, I would encourage you to double check if the details on the websites where your paper is published are correct. Much of what Google Scholar does is just indexing those websites and taking their data from there. Google explicitly recommends to ask for corrections there and not on Google Scholar. They also say state that an update to any details might take quite a bit of time, in the order of months [2]. So any recent correction to details on the publisher's side might not be updated yet.

[1] https://support.google.com/scholar/contact/general

[2] https://scholar.google.com/intl/de/scholar/help.html#corrections