The Olarm PRO's mobile / GSM connection is typically used to configure the WiFi connection from the mobile app.
WPS mode can however also be used to set the WiFi connection up in the event mobile coverage being a problem in the area where the Olarm PRO is being installed. Please follow the following guide on how to set WiFI up using WPS mode - https://desk.olarm.co/portal/en/kb/articles/wps-mode
Both connections run concurrently so if the one fails, the other connection continues running, reducing the risk of disruption and improving your security