New Dependent Parent Who Got Their Stimulus Tax Money

My father signed up with the non-filers tool back in Nov 2020 and he got all the stimulus money, for the first, second and third. But now, we were planing on putting him as out dependent on our joint tax return. But our confusion comes from the fact that he already got his stimulus and when we put down the information for the payment we received as stated on the IRS letter, which accounts for my husband, me and our two children. Then we don't know how to report that my Dad already got his money, even though he is now in our taxes as a dependent and the system assumes that there is a $1400 Recovery Rebate Credit that we should be claming. We don't want to owe the IRS any money or to have to pay back anything. How would we go about this? TIA.