alexandre Hi. Have you tried contacting the enhance team via a ticket? They're usually very responsive and helpful.
API Request Failed [404]: No availbe servers for role Application to be placed on
If that's an Enhance API response, I believe they could tell what's happening right away.
I'm using Enhance + Upmind with no issues. The hostname I used to connect with the API is the control panel's. And the API key has full permissions..