Why is Run on Pull request grayed out?

If you're unable to enable Run on Pull requests, you'll want to make sure your existing repo was not added via the Deploy Key auth method.

If it was added via a deploy key method, you'll want to use the GitHub auth method to enable CI in dbt Cloud.

To go ahead and enable 'Run on Pull requests', you'll want to remove dbt Cloud from the Apps & Integration on GitHub and re-integrate it again via the GitHub app method.

If you've tried the workaround above and are still experiencing this behavior - reach out to the Support team at support@getdbt.com and we'll be happy to help!