My site was hacked and there are a lot of technical errors there

My wordpress site has unknown outbound links which I’ll never give then I check it they’re from a post which I’ll never posted, so someone else has access to my wordpress site, then I install wordefence and do a scan there was a file which has a code which gave access to the hacker which was in functions.php in my active theme, and also there was a pages which are kinds of adds for slots I deleted it from Cpanel -> file manager there wass a folder in which there was files so I deleted that, and now there is a huge issues that my all posts and pages were linked with that Slots page and it’s now 404 but when I open posts there are no links to the deleted page but Ahref showing me that. I tried to make it 410 the slot page but it didn’t work and then I tried to open Yoast redirection tools it was showing that there is circtical issue on the site.

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