Fail to activate LoRa Server repository

Followed instructions on:
Keep getting:
gpg: keyserver receive failed: Server indicated a failure

I have check the key 1CE2AFD36DBCCA00 by:
It shows no key found!

Still don’t know why I couldn’t get access to that repository. I was just compromised and manually linked to the and downloaded the packages.
However, after my server, app-server worked precisely and I configed the gateway bridge in my raspberry pie, opened the webpage in localhost 8080. I feel lost and could someone tell me where I can find some material or guidebook about how to configure my LoRa from the server gui?