Правила Mangle

ip firewall mangle add action=mark-connection chain=prerouting comment="discord voice to_sing-box" connection-state=new dst-address-list=discord_voice dst-port=50000-50030 in-interface-list=LAN \
new-connection-mark=to_sing-box protocol=udp
ip firewall mangle add action=mark-routing chain=prerouting connection-mark=to_sing-box in-interface-list=LAN new-routing-mark=to_sing-box

Список Адресов

/ip firewall address-list add address=5.200.14.128/25 disabled=no dynamic=no list=discord_voice add address=34.0.0.0/15 disabled=no dynamic=no list=discord_voice add address=34.2.0.0/16 disabled=no dynamic=no list=discord_voice add address=34.3.0.0/23 disabled=no dynamic=no list=discord_voice add address=34.3.2.0/24 disabled=no dynamic=no list=discord_voice add address=35.192.0.0/12 disabled=no dynamic=no list=discord_voice add address=35.208.0.0/12 disabled=no dynamic=no list=discord_voice add address=35.224.0.0/12 disabled=no dynamic=no list=discord_voice add address=35.240.0.0/13 disabled=no dynamic=no list=discord_voice add address=66.22.192.0/18 disabled=no dynamic=no list=discord_voice add address=138.128.136.0/21 disabled=no dynamic=no list=discord_voice add address=162.158.0.0/15 disabled=no dynamic=no list=discord_voice add address=172.64.0.0/13 disabled=no dynamic=no list=discord_voice

документация https://xtls.github.io/ru/config/