Not sure what your setup is like, but maybe I can provide a bit of background so you can troubleshoot.
The ServerURL you use for LAMS needs to be your public address for LAMS. Even though it may be integrated with Moodle, this only creates the link to LAMS - users will still be talking directly to the LAMS server.
So if you configure server_url in the lamstwo module configuration, the url should be the same as the value of ServerURL in LAMS as well as be accessible from whereever your users need to access it.
10.21.92.29 is an internal network address, if your users aren't also on this network (e.g. connecting from home without a VPN), then they won't be able to see LAMS on this server.
Posted by Jun-Dir Liew