How to check that a room actually exists
Search the address, map the building, and compare it with the listing photos. Tour in person, or ask a trusted local person to do so. A live video tour should begin outside and move continuously through the building and room.
Ask who is on the lease or owns the property and how the room is authorized. Verify through an independent source when possible. Do not accept a door code, generic video, or a promise to mail keys as proof.
The room must exist, be available, and be theirs to rent. Check all three.