IP Multicast Settings for Vypress Chat

Installing and Using OpenWrt Network and Wireless Configuration
1

Totally noob... :grimacing::

I have an Archer C7 V5 with OpenWrt 21.02.3 installed on it and i want to know what settings to make on OpenWrt for Vypress Chat to work on my LAN?

I'm using IP Multicast:
screenshot

Thank you!