Have a read here, where there are a few options to reset the site URL after changing it in the WordPress dashboard.
Rather than reverting the change, I’ll recommend you continue and finish the change you started — since, I’m supposing, it’s something you desired.
It seems you had WordPress installed in a subfolder, public_html/wp/ and your corresponding WordPress address was https://example.com/wp/
And it seems you wanted to get rid of the /wp/ in your site address, so you simply changed your WordPress site address in the dashboard to https://example.com/
Unfortunately, that’s not enough — hence the problem you’re having.
You need to EITHER:
1) Open your WordPress site folder (via FTP or your cPanel File Manager) and MOVE the content of the public_html/wp/ folder to the root (ie to public_html) to match the new WordPress site address…
OR
2) Follow the steps in the official support article “Giving WordPress its own Directory” to configure WordPress to link the new address (ie https://example.com) to the old location of the WordPress folder (ie public_html/wp/).
Of the two approaches, #1 is the easiest and the one I recommend. But, of course, you’re free to do as you desire 😀
NB: I used the domain example.com throughout because I didn’t want to post your actual domain name publicly just in case you didn’t want that.
Good luck!
