Hi @ahmadch321 !
I opened your site in the browser to check the error you’re seeing and from the Developer Console, I see a ‘500 (Internal Server Error)’ which could be coming from various sources.
It could be exactly that – a server issue emanating from your web hosts’ server, and so you can check on that first by reaching out to your web host’s support.
You shared that you don’t have any cpanel access? Does this mean you aren’t able to log in to your web host and access your SFTP credentials so that you can see the site’s folders and files ?
If you are able to do that, you would have been able to test that you’re not experiencing a plugin conflict which is causing your server to exhaust itself, by renaming your plugins folder and thereby deactivating all your plugins all at once. To do this, navigate to /wp-content/ from your website’s root folder, and rename the ‘plugins’ file in there to something like ‘plugins.old’ for example.
You can try the same method with whichever is your current theme, after you’ve tested your plugins, by renaming your active theme at /wp-content/themes/theme-name to something like /wp-content/themes/theme-name.old.
Hope that helps.