Double-check that you are using the correct url
These logs show that the server considers this to be a bad request. So the question is: why does that server consider it a bad request? That’s not something we can answer here, but rather something to contact the publisher of the server about.
Okay, I got the same issue ; there’s obviously a HUGE bug here ; and I think it comes from the brackets…
The “JSON Export” trace logs are showing a nice payload, but it’s not what is sent.
If you replace the “Mapping” by “custom request template”, you can notice that Mendix requires the double the opening brackets ( “{{“ instead of “{“).
I’m quite sure there is a bug in the Mapping function in Mendix ….
I also created this https://forum.mendix.com/link/questions/114723
I opened a support ticket