I'm working on a system that works similarly to whatsapp web. The idea is that a user is logged in with his account via firebase on his phone. And then he wants to do a fast sign in (maybe a 10 minute session) on a computer. So I read that a passwordless sign in was possible sending a link to the users email. Is it possible to generate this link (generate it somehow) on the phone (without sending it to the email). Thanks to this, the user on the computer could for example read a QR code generated on the phone with the passwordless sign in. Help please!