Selling lease back to dealer - Paperwork

Hi All,

I'm returning/selling my lease back to the dealership 2 months earlier and the dealer had offered an incentive. I know this is becoming more common with the shortage of cars but my question is around agreement and paperwork. Is there specific paperwork such as their intent to buyout the car and to disburse me the agreement amount for me to return?

When we negotiated and agreed, they had me sign a sheet of paper with the amount they're offering but seemed pretty simple. I want to ensure that I'm covered in terms of the dealer paying out the residual value + cutting me a cheque when I return the car and want to avoid any issues with the transaction.

Thanks