Issues during setup

Hi!

I get the following error messages when trying to set up the plugin. What am I doing wrong?

Checking page optimization requests: Failed
HTTP GET 500 https://www.financesmash.de?seraph_accel_prep=eyJub25jZSI6IjY2NjQ1YWM1NTFmZjNhMmM3MGRkNTJhOTdhYzE3Njk4Iiwic2VsZlRlc3QiOiIxNzEwOTU4NjkxMzQxIiwiX3RtIjoiMTcxMDk1ODY5MS4zNDEifQ%3D%3D
Server Address: 173.236.136.187
Request headers
User-Agent: WordPress/6.4.3; https://www.financesmash.de
Response headers

Checking pages external caching: Failed
HTTP GET 500 https://www.financesmash.de
Server Address: 173.236.136.187
Request headers
User-Agent: WordPress/6.4.3; https://www.financesmash.de
Response headers

Tanks for your help! I appreciate!

Tim

The page I need help with: [log in to see the link]