Can't play with friend cross platform

vahida1157​ Console players are the ones with the option to opt in and out of Cross-Play, (so your friend would need to check their in-game settings to see if the Cross-Play setting is enabled), and also have them check their privacy settings to see if they can be searchable as well.

Furthermore, since you're on PC and they're on PS5, while they're offline, you'll only see them in your friends list by their EA ID, (if you had friended their EA Account as well), otherwise you'll only see their PS5 username when they're online, (if you're playing through Steam, you won't see your EA friends in the friends list unless they're online as well).

More information can also be found here: Apex Legends™ cross-play: how to play with friends