Don't file an amended return yet.
The IRS says that the IRS will correct your refund automatically, although it may delay payment. See questions G2 and G3 here.
https://www.irs.gov/newsroom/2020-recovery-rebate-credit-topic-g-correcting-issues-after-the-2020-ta...
Wait until your refund is paid. If the IRS automatically reduces your refund by the amount of the rebate, then you don't need to file an amended return. Only file an amended return if the IRS does not automatically correct your refund.
