No, you do not need to wait for the 2020 federal tax refund before you can file the 2021 tax return.
Go ahead and complete the 2021 tax return and where asked to enter a 2020 AGI enter a 0 (zero) so that you can e-file the 2021 return.
The IRS will not have your 2020 AGI in their database since they have not fully processed the 2020 federal tax return.
