Why am I not able to push transactions to the GST portal in spite of enabling API access?

You will not be able to push transactions the from Zoho Books to the GST portal if you’ve entered an invalid username or GSTIN in Zoho Books. To edit the username and GSTIN:

1. Click Settings and select Taxes from the dropdown.
2. Select your GSTN below GST Settings.
3. Make the necessary changes and click Save.