End device does not recognised by lora server web interface

wsnod As picture shows, I followed a video on youtube to configure lora server web interface . Gateway has been configured succesfully but end devices did not. I am new in lora server please help
Note: my end device model : Wisnode Lora Rak Open Source Hardware (based on rak811)

No need to post twice: https://forum.loraserver.io/t/device-last-seen-at-never/5294.