Most macOS applications heavily rely on the system proxy and security settings. Modifying these settings is a system-wide change which will affect almost all applications and system services. To reduce the overhead of these changes ensure that you use strict proxy scoping rules and you remove old CA certificates as soon as they are no longer needed.
The system proxy settings are managed separately for each network interface. Open "System Preferences". Navigate to "Network". Select the adapter for which the proxy settings apply. In most cases, this is your WiFi network card. Click on the "Advanced" button and navigate to the "Proxies" tab. You need to select both "Web Proxy (HTTP)" and "Secure Web Proxy (HTTPS)" options. Type your proxy server hostname or IP address. If you are configuring a local proxy then this is "localhost" or "127.0.0.1". The port is your proxy port in your Feeds settings. For example, if you are using proxy feed "proxy://localhost:8080", the hostname is "localhost" while the port is "8080".
This change will force all traffic using the configured network interface to use your proxy settings. This also applies to encrypted traffic. Therefore you need to complete the following setup to avoid abnormal system behaviour due to lack of proper CA certificates in place.
Open AppBandit. Navigate to "Preferences" from the application menu. Click on on the "Certificate" section. Identify the "default-cert.pem" file and click on the "System Install" button to load the certificate your keychain.
Once imported, ensure that the certificate is marked as trusted. Open the certificate from the windows of the "Keychain Access" application. Expand the "Trust" drop-down. Select "Always Trust".