Note: It is recommended to open up the affected URL in your firewall instead of using a proxy server. A proxy server can introduce addition delays and potentially other problems related to transforming data from the source site.
If your Events2HVAC server has to use a proxy server to communicate with an external URL, you will have to manually modify a couple of configuration files to allow this to happen. This change will affect all http traffic in the application after it is applied.
You will need to stop the Events2HVAC service and close the client application and modify both of these files located in the application root directory:
Copy the <system.net> element section (in red) from the snippet below and insert them in both of the files in the bottom section (before </configuration> element). You can test it in the events2hvac.exe.config file first to make sure it works before changing the service.exe.config.
Whenever you are modifying a .config file, you should keep a copy of the original in case you need to revert back. A typo can prevent the application from working.
For more details on the configuration elements, see https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/network/defaultproxy-element-network-settings