I re-forked your repository and ran through the same process, which seems to have worked for this example: https://chadcurtis.github.io/nostrpop/
Aside from setting the page deployment source as 'GitHub Actions', the only other action that may be required is starting the pipeline once more. Specifically:
1) Going to the 'Deploy to GitHub Pages' pipeline - https://github.com/bitpopart/nostrpop/actions/workflows/deploy.yml
2) Clicking the 'Run workflow' button to the right of the page, followed by clicking the second green 'Run workflow' button in the popup that appears:
