site address problems

installed wordpress onto a server (WordPress URL: https://northstarlabels.com/everettbaylodge/wordpress). For testing purposes the site address was set to the same address. Now the site is live and I need the site address to reflect the clients domain name of everettbaylodge.com. The problem is that when I switch the Site URL to everettbaylodge.com, the only page that shows up is the home page – all other pages say “Cannot be found”. Initially I thought that changing the links in the menu from the actual path (https://northstarlabels.com/everettbaylodge/wordpress/page-title) to reflect the site address (https://everettbaylodge.com/page-title or https://everettbaylodge.com/wordpress/page-title) would solve the problem, but then I get a internal server error.

Just set up another site exactly the same way on the same server and it works fine. please help!