GSTN issued Guide and Instructions for Direct API Integration with Any of the 6 IRPs for E-Invoice
The GSTN vide Advisory No. 615 dated November 17, 2023 issued a comprehensive Guide and Instructions for Direct API Integration with Any of the 6 IRPs for E-Invoice Reporting.
Tutorial - https://tutorial.gst.gov.in/downloads/news/e-invoice_api_integration_guide_irps.pdf