Log in to the GST portal
Go to Services
Select Returns
Select Returns Dashboard
Choose the financial year and return filing period
Click Search
Select GSTR-3B
Click Prepare Online or Prepare Offline
Fill in outward supplies details
Fill in inward supplies liable to reverse charge
Enter eligible ITC details
Enter exempt, nil-rated, and non-GST inward supplies details
Enter interest and late fee details, if applicable
Verify tax liability
Offset liability using available cash and credit balance
Preview the return
Submit the return
File the return using DSC, EVC, or EVC OTP
Save the acknowledgment and ARN for records