From this Lock Details page, scroll down to the Access section and click on Access Codes.

Tap on an available Secondary Code.

If desired, you can name the code Photographer. Then, you type in the custom code you’d like the photographer to use. This code must be between 4-8 digits and cannot begin with a zero. Then, click Save.

You will see a circle made from red arrows; this signifies that the code is pending an update. This means the registered owner must be within Bluetooth range of the lockbox to open the Vault app and sync the update. Once this has occurred, the arrows will disappear and the code will no longer be pending.