Hello Piotrek,
The problem does relate to your themes. I clicked on the wrong ZIP file when I was setting up the website.
I just set up a new user. I presume that is what you meant by “second administrator”.
When I go to growinglove.club/wp-login.php and login with my new credentials, not much happens. When I click on the blue “Setup Integral Pro” button, the error message says “Sorry, you are not allowed to access this page.”
Any other suggestions?
Peter