Making external get request with Express

so I have the following Scenario; I have a private API key that Angular will show in XHR request. To combat this, I decided to use Express as a proxy and make server side requests. However, I cannot seem to find documentation on how to make my own get requests.

Architecture:

Angular makes request to /api/external-api --> Express handles the route and makes request to externalURL with params in req.body.params and attaches API key from config.apiKey. The following is pseudocode to imitate what I'm trying to accomplish:

router.get('/external-api', (req, res) => {
  externalRestGetRequest(externalURL, req.body.params, config.apiKey)
  res.send({ /* get response here */})
}

via Moshe