Display raw xml from REST query

I am quite new to all of this. Right now we have a QR code on our employees id card that stores a user id. When that card is scanned, it pulls up a url from a website and displays raw xml data filtered by that user id.

Here is the developer page: https://litmos.zendesk.com/entries/2...-Developer-API

I have done all this and it returns the raw API perfectly, now what (and how) would be the best way to display the unreadable raw data as a simple list on an html page?