Connecting #irc to #Matrix ::
1) join a irc channel on matrix
eg)#freenode_<#channel>:matrix.org
eg)#wikipedia-en:libera.chat
2) start a DM to set your nick
@appservice:libera.chat
"!nick <yournick>"
eg) "!nick SomeNick777"
3) Now auth your nick
!username irc.libera.chat <your NickServ username>
eg) !username irc.libera.chat SomeNick777
4) Now store your pass
!storepass irc.libera.chat <your password>
!storepass irc.libera.chat BlahPa$$Word