Gstr 1 and 3b

sir
i sale through amaizon . i do not issue any invoice. amaizon has issued invoices on behalf of my gst no. and tax has also paid by amaizon taxable value in the invoices is including comission
of amaizon
now which invoices and value should i fill in gstr 1 and how shuld i file 3b if tax has been paid by amaizon
please guide me
thanking you