How do I amend my 2020 tax return because I made an error on a tax credit form and i got extra money, what's the next step?

i got more tax credit than i should have gotten. i accidently put the wrong information on a tax credit Educational Opportunity Tax Credit for the state of Maine. i just got the credit in my checking, what should i do to correct this because i was given too much money?
more info. i was paying for but student loans were paused because of covid and i forgot i wasnt auto paying for loans because they paused auto pay as well. so i only have 3 months out of the 12 months that ive been paying loans. but I accidently put for all 12 months. How do i give the money back minus the 3 months i did pay, back to the state of maine.