Invoice can be revise after filling gstr1

If you discover an error in your GSTR-1 return after filing, such as an incorrect item quantity on an invoice, you cannot directly revise the filed return. Instead, any corrections must be made in the GSTR-1 return for the subsequent month or quarter. While some details like GSTIN and date can be amended, it's important to note that the invoice amount and quantity generally cannot be changed in a subsequent return.