Feature request: manual Public IP

Hi, could you add a field in which we could specify the public IP or domain name we want instead of trying to find it automatically ?
I have a double nat problem and I can’t configure the primary equipment, which is located at my ISP’s.
However I can access to my Plex Server with the IP of the second equipment, configured correctly at home.
If I want to enable the remote access, I need to specify which address my server has to give to the internet platform but it’s determined automatically and only sees my primary equipment IP…

https://support.plex.tv/articles/200430283-network/
‘Custom server access URLs’

Thank you so much ! I works now !