Unable to setup gateway bridge in Ubuntu from AWS

Dear Sir,

When I type the command sudo apt-get install chirpstack-gateway-bridge, I have a message stated as E: Unable to locate package chirpstack-gateway-bridge. Please advise me how to proceed from here.

You new to add the ChirpStack Debian / Ubuntu repository first. See:

https://www.chirpstack.io/guides/debian-ubuntu/#setup-chirpstack-software-repository

Thanks I got it work. Now I have an issues with the chirpstack-application-server setup. Please see the image below and advise me how to resolve the problem. Thanks.