As of now, you cannot transfer your crypto from Robinhood to Coinbase. Robinhood is a commission-free stock trading platform that also offers cryptocurrency trading.
Coinbase is a cryptocurrency exchange that allows you to buy, sell, and store digital assets. The two platforms are not connected, so you cannot transfer your crypto from Robinhood to Coinbase.
This may change in the future, as both Robinhood and Coinbase are constantly evolving. For now, if you want to trade on both platforms, you will need to do so with two separate accounts.