You can add ERC721 tokens as one-off prizes to a Prize Pool.
First you'll need to transfer the token to the Prize Pool. The Prize Pool needs to own the token before it can be given away.
The Prize Strategy needs to be aware of the token so that it can award it to the winner. The token must be owned by the prize pool, or else it can't be added.
If you're the pool owner, you can use the reference app to administer the pool