Where else to register a port for Bitrix?

Question

1C-Bitrix

Good afternoon everyone. I ask for your help. Bitrix was installed on a server with a dedicated IP plus port, .te. it is available at xx.xxx.xxx.xxx:81 but the port in the system is ignored, in the administrative panel, when saving any settings, it is reset to IP WITHOUT port.
Settings > Module settings > Main module:
Site name: xx.xxx.xxx.xxx:81
Site URL (without http://, for example www.mysite.com): xx.xxx.xxx.xxx:81
Settings > Product settings > Sites > List of sites >
Server URL (without http://): xx.xxx.xxx.xxx:81
where else to register? Because all of the above is written and did not help. Thanks in advance

Answer 1

This must be indicated on which port the web server will be, in the web server itself and not in Bitrix

Answer 2

try to specify in .htaccess that the root directory is a url with a port.