GSTR1

firstly try to upload GSTR 1 with late filing fees or else give approval to your customers by accepting Invoices.

check your invoice number ....
i am sure you did mistake in your invoice number check deeply

and till now late fee is applicable but where have to pay this late fee dont know anyone ... i filled december 3b after filling gstr 1 today no late fee applicable there

let see where and how to pay fee till forget about late fee and consuntrate to filled your gstr 1 quickly

keep in mind file july seprate (monthly and quaterly not matter)