How to adjust tax liability in gstr-3b due to sales return?

For example-

Goods Sold - During September'18; Sales Return made - in October'18; Credit Note Issued - in November'18.

The assessee files GSTR-1 in quarterly mode.

Therefore, the details of credit note issued during the quarter Oct-Dec to be reported in the GSTR-1 in January'19.

Now the query is - due to sales return the tax liability must be adjusted,i.e., the supplier has to pay lower tax than he already deposited. But how to adjust the same at the time of filing GSTR-3B as there is no particular column in which we can declare the credit note issued. So, if the supplier files the GSTR-3B without considering the credit notes then he has to pay more tax. Further, while he will be declaring the credit notes issued in GSTR-1, mismatch will occur.  Then, how to deal with the same? Please suggest.