You meet in the same public server — there is no friends-only room
The creator’s own experience description states it: “Race friends across multiple game modes!” (read 2026-10-01). Nothing here needs to be reverse-engineered.
The official API reports private servers disabled for this experience (createVipServersAllowed: false, read 2026-10-01), and a server holds up to 80 players. A group session runs alongside everyone else.
Whether you can follow a friend in is decided by their Roblox visibility and privacy settings and by free space in their server — not by a WikiRace menu we have never seen.