That was it! Thank you so very much!
I've been following a guide on linuxbabe.com's website. I am running Ubuntu 22.04, postfix, mysql and the latest postfix from the website. When I open up the setup.php page I get the following message: Your setup_password is in an obsolete format. As of PostFixAdmin 3.3 it needs regenerating. I used php -r 'echo password_hash("password", PASSWORD_DEFAULT);' to get the hashed password and copied it into my config.local.php file as instructed I still get this message every time I pull up the page....
I am having this same problem on Fedora 24.