When using the HTTP Request activity that’s auto-generated by creating a connector in Connector Builder, there’s no way to get the full endpoint URL (for logging, emails, troubleshooting, etc).
Because the base URL is supplied by the Integration Services Connection, we don’t supply it at runtime - so we need to be able to get it back from the activity.
You will edit the xaml in a text editor → search for the targeted HTTP Request with the connector → get the gzip value for the ConnectorHttpActivity → decode it under GZIP to Text Tool → analyze the RequestPreviewParameters to see the whole request built in the backend.