where do I report receiving crypto as a gift, if I have not sold it?

A gift is not taxed and doesn’t have to be reported. You should know ye cost basis which is that of the donor. 

If you received the crypto, you don't report anything.   If you're the one who gave the gift, you don't report it either, unless it exceeds $17,000 per recipient for 2023 ($18,000 for 2024).

As mentioned above, you will need to know the cost basis of the crypto, as it will be reportable whenever you sell, use, spend, or otherwise dispose of the crypto property.   

How do I determine the cost basis of stock (crypto is treated the same way as stock) I received as a gift? 

The basis of crypto you received as a gift is determined by the giver's original cost basis and the fair market value (FMV) of the crypto at the time you received the gift.