Why Does HeyGen Error Only When Triggered Through Gumloop Automation?

Hi! I’m having trouble getting HeyGen to run successfully through my Gumloop automation. When I create videos manually inside HeyGen, everything works perfectly, so credits and settings aren’t the issue. Gumloop support checked the workflow on their end and confirmed there’s nothing wrong with the automation or how it’s configured. That means something about how Gumloop is passing parameters to HeyGen’s API is causing the error — but I can’t figure out what.

Has anyone run into this before, or is there anything specific I should check in the API request format when connecting Gumloop to HeyGen? Any guidance would be greatly appreciated!