dnkrupinski
Hi, welcome to JotterPad forum!
I have checked your Wordpress URL and if you have enabled XML-RPC:
https://testpress.dnkrupinski2020.de/xmlrpc.php
It should output:
XML-RPC server accepts POST requests only.
Your blog page displays the output correctly. Hence, the URL should be correct.
I will need to escalate this issue to my team. I believe that you have filed a ticket in our live chat page. We will get back to you asap. Thanks!