Just now I filed GSTR-3B for the month of August 2017. As a fresher, it gave me some hard time. Let me share..
To create a payment challan, I opened Challan page in new Tab. It helped me to fill IGST, SGST and CGST values without any error by looking at the GSTR-3B submitted details. After creating challan, I couldn’t make payment using Online payment option as my Browser’s Adaware Ad block plugin was blocking Net banking site from loading. If the bank’s net banking page is not loaded in the first attempt, it will not work even after a refresh. Hence I was forced to create a new challan and try after disabling the Ad blocker plugin. Anyhow after making the payment, I clicked on the redirect button and I was able to verify the amount in cash ledger. How to offset was the next question.