Share links with external ip, not local ip

when i copy share links of files i have local ip in address, but i want to send shares to external users. If they use that link the get my local ip, not internet -facing external ip.
How can i change share links to have external ip instead of internal ip?

-Snap instal, latest version
-no domain name, only external ip with custom port configured, is accessible form internet
-login permitted only from my local network ip (app do this)

The purpose : office colleagues need to share files from this server to some colleagues out of office, so when they copy link to send it by mail, they need all link correctly displayed, with external ip.

What i can see is if i login with local ip, link shares have local ip, and if i login to localhost, then link shares have ‘localhost’ instead of ip (this is a bug, maybe?). The same stand for Settings - Mobile and Desktop - Server address.

I could connect from external ip and custom port to have correct share links, but i don’t want internet users to have login page enabled (specific app blocks it).

So there is any way to have external ip and port added instead of local ip in shared link when i click COPY button of share link?

Thanks, it would really help me, i also want to implement this into my work company!

by installing a local nameserver and share by domain name and not by IP address