Without a DNS server that is accessible, you cannot connect using a FQDN; there is no path for a computer to resolve the IP address from a FQDN. DNS provides this lookup table. You could define the favorites to the IP address, which would solve the DNS side, but NOT the SSL side of the equation. SSL requires the FQDN.
You might be able to go into each computer's etc/hosts table to get around DNS and make the mappings there, but that is poor practice at best.
Also with the SSL, you will need to have the root certificate installed on each machine. The major CAs (certificate authorities) are all built into the OS certificate structure, BUT as your server has no access to the outside world, these cannot validate to the outside world. As a result, you would need to installed the root certificate on each workstation, in order for the SSL validation to work.
IF you workstations can see the outside world, then they could validate against the CA, BUT the FQDN would have be registered in some public space in order for the public DNS structure to recognize the FQDN and even then, it could not map against the private IP address of the server, so although this would technically resolve, it would have no known target to go to.
For my internal network, I use Pi-Hole as my DNS server; for clients on private networks, Microsoft's Certificate Authority Server can generate a FM templated SSL key pairs structure which you can then use.
Interactive container fields require the SSL to be working. That's just the way it is.
An alternative process would be to script a button that exports the temp path and file name to that temp directory, and user Open URL to show it. That way, it opens in the default PDF viewer as defined in the OS, which is often more flexible than the internal container structure.
