Here in Lumiose Pokemon Legends Z-A Side Mission Full Walkthrough and Guide

Unlocked after finishing all other Side Missions.

Note: This is only available through the Mega Dimension DLC.

Urbain needs some help at Quasartico and hopes you can do him a favor.

[1] After finishing all other 199 Side Missions, enter Hotel Z.
・Urbain/Taunie left something in his room and wants you to help him read a password for them.

[2] Go to Room 201.

[3] Investigate the magazines in the bed.

[4] Tell Urbain/Taunie that the password is "Gp58JatW".

[5] Battle Urbain/Taunie outside the hotel and win.
・Here is their profile.

[6] Meet Urbain/Taunie on the roof.
・Enjoy the heart-to-heart!

・₽ 10,000
・Gold Bottle Cap x 10
・Rare Candy x 10
・Seed of Mastery x 10