Hi @rzaneti ,
This is an API from a service my client uses to send SMS' I do not have access to error logs unfortunately.
I also cannot be using other external tools other than the allowed ones due to security reasons.
What I can tell you is that I can only perform the API call successfully on Postman so far. I have also installed PAD on my own company machine and no success either (postman works on my machine too).
Here is a screenshot of all my configuration on both sides:




The body has " on one side and ' on the other, that's because I was testing with both and I've tried changing it around but still hasn't made any difference.
Not sure if this will help with anything but I'm all out of ideas here 😄
Thank you,
Marian