Missed invoice of August 2019

This discussion addresses how to handle an invoice from August 2019 that was missed for the 2019-20 financial year. The sender is seeking guidance on whether to pay taxes and declare it in GSTR-9 for that year, or if it can be filed in a later return. They are also asking about the availability of Input Tax Credit (ITC) for the paying party and the correct filing procedure, considering deadlines for GSTR-1 and annual returns.