The easiest way is to scan the QR code that you see on your PS5 screen using the mobile app. To do this, launch the mobile app and then tap on your profile avatar.

How to scan a QR code on an Android phone As QR codes have become more common, more manufacturers have built QR scanners directly into the default camera app.

Never heard of it. It's also worth mentioning that you can connect your Xbox to a Discord voice channel from a PC too. But to do so, you'll need to scan a QR code using the Xbox Mobile app to join.