The APK can be found by going to the "Checks" tab below the title.

There is no APK.

There is nothing to test here. Why do you want the APK, @Symbian9?

Why do you want the APK

To test latest dev-branch builds. There no any automatic built APKs (artifacts) provided by CI (is it common issue to GitHub Actions in NewPipe repo?)

N.B. I see that there is just manually uploaded APK in #9290, but its not automatic CI built artifact.

Many pull requests has next note in description:

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR.

But it seems like there are no CI-built APKs (artifacts) on the "Checks" tab in any of such pulls.

It's there in most of them. This PR just didn't change any app code at all, so the APK wasn't created. Look for the RC issue if you want to test.

I went to PR 9290 and the APK is exactly where the "APK testing" section describes. Are you opening that page while signed in?