There are Two options to change User Codes:
Mobile App:
1) Go to your pages on your left side
2) Select users
3) Here you can manage, add, or delete your Users
AT THE PANEL:
1) Hit settings gear on bottom right
2)Enter Master Code (Default 1111)
3) Select Users.
4) Here you can manage, add, or delete your Users and Duress code.
https://www.youtube.com/watch?v=BuZRyqA2nOY&list=PLGdtWAgjdwqF8YRqXYO3dwq9qEkxdxdiO&index=4