Hi and welcome back to the forum! Please don’t stalk existing topics; only create your own ones for the issue you’re having. I split it up for you; also, this is your first and last chance. Another violation I see will result in your post on the other topic being flagged and deleted.
As for your issue, I see a 500 error caused by some wrong rules on your .htaccess file (yes, it’s generated by the server and not by the browser), so you have to correct them or delete any wrong rule you see before your website can work again. If it still doesn’t work on your side, try the workarounds on this article: