We tried out the solution of balayan_cpp and i can confirm - it works. Many thanks to you! @AdamStehlik It won't help. I tried that and they told me that they aren't a technical support for Xcode Cloud, linked me the broken official documentation and advised me that i should use a TSI. But - you only need to change it once, right before you create the OAuth Application in GitLab. Go through the Xcode Cloud Setup and reverse the change right after the Setup was successful. Or wait for the next GitLab update so that the change will be reversed automatically. We did it like this: Inform the team about GitLab not being available/working in the next Morning for an hour. Adjust the value the next morning. Restarted GitLab (doesn't work without it) Set up Xcode Cloud Done. In our case, we can afford to wait for the auto-reverse.

@balayan_cpp No. I plan to use a TSI for this topic. In my opinion the situation is - GitLab updated the structure of its secret - and Apple did not do the same on their Appstore Connect page. They should, since they say that Xcode Cloud works with GitLab. My expectation would be - the Appstore Connect web form and its underlying logic will be updated to use the new GitLab secret structure.