webservices isn't needed for a computer browser to access a moodle site. webservices intended for mobile support.
From your description, sounds like you have a Ubuntu server (where moodle code/application) resides in a private network ... 192.168.0.0 - 192.168.255.255. That's a private IP meant for local LAN or private WAN access only. That network and any server on that network cannot be accessed from public internet without a boundary firewall set up to allow a mapped public IP address which you control to a private IP address.
All that to say .... networking comes before application ... and your issue is one of networking ... not necessarily moodle ... although config.php and wwwurl do come into play ... your moodle is the end point.
Please see and read:
https://ubuntu.com/server/docs/how-to-install-apache2
then
https://docs.moodle.org/403/en/Masquerading
(networking)
'SoS', Ken