the thing is that robin hood it's not a trading app, you don't buy a share on your name, those shares are pooled and bought and selled off the official market.

If you want to invest, use a real broker, but then you will have to pay commissions.

Also, have in mind that even if they say that they are commission free, you pay with higher spreads, so if the transaction price is 1, robinhood will sell it to you by 1.02 and bough by 0.98, getting a margin from you each time you make a transaction with them.