There is no Web page or REST API command that shows service pin messages from an external device (like an external LON device), but you can use MQTT or WebSockets to see incoming service pin messages.
The following MQTT commands can be used from a SmartServer ssh terminal or SmartServer Console: choose one
1. Service Pin message for devices on any SmartServer:
mosquitto_sub -v -t glp/0/+/ev/join
2. Service Pin message for devices for a specific SmartServer ( e.g., 17q3awh):
mosquitto_sub -v -t glp/0/17q3awh/ev/join
IAP/WS general purpose WebSockets can also be used to see external service pin messages as WebSocket updates.