Most of the pain around GST filing is not the tax. It is that the invoices were raised somewhere that did not capture what the return needs.
What a return actually wants
Place of supply, so it knows whether to expect CGST and SGST or IGST. The customer’s GSTIN. HSN or SAC at the line. The taxable value separated from the tax. If those were captured when the invoice was raised, the return is a view of data you already have.
If they were not, somebody spends the first ten days of the month rebuilding them from a Word template.
See it with your own data
Start free, import a spreadsheet of your customers, and raise a real GST invoice in the first ten minutes. No card, no sales call.