Hey @DannyF!
Apologies for the late reply here. It looks like you were able to get this solved with @Kenny by setting your resource to share your OAuth credentials between users:
Just wanted to post this here in case any other users run into a similar situation. Workflows don't have a way to run auth flows that require user inputs so setting your auth flows to not require them with settings like sharing credentials or using client credential flows is necessary.
Let me know if there's anything I'm missing!