API connector error - Bank aggregator

Hello everyone ! This is my first topic here !

I need your insight on the API connector. I am currently trying to connect a bank aggragator (https://www.budgea.com/) with the API connector on my bubble app but my current setup call to log is not working.

At my stage, I want to implement a web-view in my bubble app. During the setup call, I correctly reach the local domain called “rob-sandbox” but after connection on the budgea app this message is adressed to me :
API Connector error: the Oauth2 API Budgea is not configured properly - Received error from api

For you to understand completely, I joined you the different links put for the setup call :

I hope someone already had this kind of problem and can help me !