Following instruction on this page you can test if your host has accses to the public internet.
On the machine that runs your service run command below to prove that it has access to public internet:
echo quit | timeout 3 telnet 8.8.8.8 53
The command will try for three seconds to connect to a commonly knonw name server hosted by google (port 53 is the default port for DNS services).
TIP: If google services are not available in your organization, please pick a suitable alternative IP address port pair. In the UK echo quit | timeout 3 telnet 1.1.1.1 53 is probably a good pick IF you are not limited to N3/HSNC. 1.1.1.1 is cloudflare managed domain server.
Expected success output
Trying 8.8.8.8... Connected to 8.8.8.8. Escape character is '^]'. Connection closed by foreign host.
This means that your machine can establish a network connection to a google server on port 53.
Expected failure output
Trying 8.8.8.8...
Absence of `Connected to 8.8.8.8. indicates that your client cannot establish a network connection to a http://google.com server on port 53.
Action
This is most probably an issue in your network.
TIP: Try to resolve the issue within your organization.