The guest has already been associated with an RFID tag at the time they check in. (Maybe they are an existing customer or the RFID tag is associated at the time of purchasing the lesson.)
Navigate to the On Mountain Check In portal - https://appt.roomboss.com/ui/skischool/index.jsf
Click the Load/Refresh Lesson button to ensure the information is up-to-date.
Click on the RFID tab, click the Scan Guest button
Scan the guest’s RFID tag (lift pass)
A list of available lessons will be shown.
Find the correct lesson, click Check In