For exporters, an e-invoice must be generated at the same time as the main invoice, as it's required for the invoice to be valid. If shipping bill details are only available later, you'll need to amend them in your GSTR-1, as e-invoice data auto-populates. This applies even when exporting under a Letter of Undertaking (LUT).
30 March 2022
we are exporter , is it necessary to generate in e voicing same time while creating e way bill or we can generate after receiving shipping bill copy
31 March 2022
Ideally you will have to generate einvoice as and when you are generating your invoice. Both will be simultaneous. Your invoice will not be a valid invoice if it does not contain QR code of Einvoice. In case where shipping bill details are known later you will have to amend such details in GSTR-1 since details from einvoice will get auto populated in GSTR-1 For further clarifications you may contact me