Input Issue

Hi Sir,
I wish to know the following point...
Assuming that a Interstate Supplier sent goods on 01/01/2021 but Invoice date was 31/12/2020. Recepient received goods on 05/01/21.
Accordingly the above is reflected in Dec.2020 - 2A & 3B by the supplier. Since the recipient received in 05/01/21, it is accounted in the books recipient in Jan.-21.
So, the recipient takes Input manually in Jan.2021 GSTR-3B. But as per new Rules, the Portal will alert for manually changes the respective field.

Kindly advise the correct method.