Not sure. Oftentimes services that say they require an SSN will in practice accept an ITIN, so I guess you could always try
Have you tried signing up for a regular, US-based, Robinhood account yet? I assume it’s the same requirements.
EDIT: Actually, it says you’ll need to be a citizen or permanent resident, or possess a valid (I assume, immigrant vis). That might make it a bit trickier…