Hello @bolat1972
Glad to help!
It looks like XML-RPC is not responding correctly. Please make sure XML-RPC is turned on for your site and is set up to respond to all content types.
I would recommend that you check the following:
1) Do you use any security plugins that may block access to this file? If so, could you try to disable them? You might also want to check your site’s .htaccess file for any rules that might be blocking access to the?xmlrpc.php file.
2) Does your hosting provider block access to this file? If you don’t find any plugin that may block access to the file on your site, I would recommend that you get in touch with your host.
3) If you are using Cloudflare, could you please try pausing it as described here?
https://support.cloudflare.com/hc/en-us/articles/203118044#h_8654c523-e31e-4f40-a3c7-0674336a2753
After you’ve paused it, try again to see if the issue persists.
Let me know if you have any questions.
My best regards,
Michelle C.