That is fine that you received your refund. The IRS actually prefers for all payments and refunds to process before you try to amend. Also, the amendment Form 1040X and instructions are not yet final. You can do what you want with that money, or you may choose to use it to pay what you owe to the State. It is your choice.
When the amend instructions have been posted and form
1040X finalized (estimated to be ready by mid-February), they will appear in this TurboTax FAQ:
https://ttlc.intuit.com/replies/5114064