well viset the website coinos.io and add it to your phones home screen witch will give you a bitcoin on-chain address and a lightning address like Username@coinos.io

then buy some Sats (smallest denomination of BTC) though ever your bank if it allows it or an exstange, then send them sats to the on-chain address on coinos

then when you click the lightning icon on website or use the invoice and past it in like the one I have shared in this post

then take the lightning address the wallet gives you and edit your profile and put it in the NIP-07 box that way if I then click the lightning icon it will fill that address in my wallet app that uses lightning and or shows me a QR code to use to prefill with, this is only for receving on the lightning network.

this happen instantly because it take you SATS off chain to move at the spead of light for you to then put back on-chain when you want to

the reazon I understand it called ZAP is because your sending light though lightning network and when that happenes in real life that called a zap so i think the consept in name is because of that

lastly some noster clients allow noster connect this allows you to connect coinos to your noster client and be able to zap others though the lightning network