Log in to the GST portal
Go to Services
Select Returns
Click Returns Dashboard
Choose the financial year and return filing period
Select GSTR-1
Click Prepare Online or Upload JSON, as applicable
Enter invoice details for outward supplies
Add details of B2B, B2C, exports, credit notes, debit notes, and other applicable transactions
Save the entered details
Review the summary of the return
Validate the data for errors or mismatches
Generate the return preview if needed
Submit the GSTR-1
File the return using DSC, EVC, or other permitted method
Download the acknowledgement after successful filing
Verify that the filing status shows as filed