Made some progress @gol19
Needed to add a file
root@foreman:/etc/apache2# cat sites-available/06-pub.conf
Alias /pub /var/www/html/pub
<Location /pub>
<IfModule mod_passenger.c>
PassengerEnabled off
</IfModule>
Options +FollowSymLinks +Indexes
Require all granted
</Location>
then enable the site, and the alias and autoindex apache2 mods
a2enmod alias
a2enmod autoindex
a2ensite 06-pub.conf
looks like most setup guides assume you have katello running which sets up /pub based on my limited understanding.
https://github.com/theforeman/puppet-foreman_proxy_content/blob/master/manifests/pub_dir.pp
https://github.com/theforeman/puppet-foreman_proxy_content/blob/master/templates/httpd_pub.erb
After doing this, I was able to get my host past the PXE loader screen, it loads the Ubuntu22 installer but prompts for manual installation input. Hopefully I can pick up from here the rest of the autoinstaller setup