What if the store issues me with an electronic tax invoice for my goods?

You can make a TRS claim with a valid electronic tax invoice. If the value of your electronic tax invoice is $1000 or more it must contain your identity.

For claiming at the TRS facility

You do not have to print out a copy of your electronic tax invoice. When you make your TRS claim, present the tax invoice that is on your device, along with any other tax invoices you may have, your passport, boarding pass, and your goods if requested, to the officer who will process your claim.