Cannot add credentials to Jenkins Bitbucket Branch Source Plugin

Question

I have installed the Bitbucket Branch Source Plugin onto my Jenkins server (version 2.249.3) in order to trigger builds on a git push. I've followed all guides I can find, but cannot seem to be able to add my credentials in the drop down menu on build configuration for a multibranch pipeline.

Selecting credentials for plugin

I have a few global credentials saved as shown below - but none of them are showing up in the drop down menu and I can't work out if it's a bug or if I've done something wrong.

List of credentials

Any ideas?