How do I recieve and use roomlist name?

How do I That before joining room ?

Please explain step by step

After "On Logged In" triggers, you can "Request Room List"

In the "On Room List" event, you can use the room list expressions:

ListRoomCount

After On room list, the number of rooms in the received list.

ListRoomName(index)

ListRoomPeerCount(index)

ListRoomMaxPeerCount(index)

ListRoomState(index)

After On room list, retrieve information for a room at an index in the received list. The state can be one of "available", "locked" or "full".

For example, to list all available room names in a text object, you could put in a subevent:

Repeat ListRoomCount times - TextObject - Append "ListRoomName(loopindex)&newline"

Or you can add all the rooms to a list object, so that users can select a room to join.