There are a couple of steps to this process. First, confirm that this teacher/staff member is an active user in your building. If they are able to login successfully or are located within your User Management section, they are an active user.
Next, the missing teacher/staff member will need to confirm that they have their Profile Settings set correctly. To do this from their dashboard, that user will need to click on the gear underneath the name of their school. On the Profile Settings page, under “My profile”, that user will need to make certain that they have toggled to the right (blue for “Yes”) for the “Do you want adults and students to be able to create passes to/from you?” Once they have updated that information, they will click the blue “Save changes” button. This will now allow this user to be available for selection in the drop-down menus.
For more information on how to set up your profile - from your Pass interface, click on Training > Documents > Administrator Guide and scroll down to “Setting up a Profile”.