WinIRC

WinIRC is a UWP IRC client for windows 10 and higher.

First, click on WinIRC on top left section of window. click on Manage servers and create a new server

replace bnc.example.org with your server, enable Secure connection and set port to 31337 as shown on picture and replace password with User/Network:Password, for example if your network if ircnow, your password is abc1234 and your user is john it would be like john/ircnow:abc1234 then, click on save button and connect