Quick answer
There is no Friend Pass for the launch version of We Were Here Tomorrow. Plan for both players to have their own copy of the full game.
What both players need
Each player runs the game in their own account session on a supported device. Connect through an online lobby or direct invitation. Playing in the same room does not add a one-device split-screen mode.
Friend Pass is not the same as family sharing
A store’s family-sharing feature does not by itself mean one licence can run two simultaneous full-game sessions. Do not treat a sharing label as a free guest invitation.
The historical Demo is a separate release, and the Fan Edition’s extra art or wallpapers are not a second playable copy. A pass from another We Were Here game does not grant full-game access here.
Already have two copies?
Follow the cross-play and invitation steps, or read about playing together in the same room.