Teams Standalone App

I have attempted to create a Teams app using App Studio that will present a website front page.

I can only seem to get this working by creating a website app on a Teams channel but not as a standalone App. When I install the app I created on App Studio, it does not seem to grab the URL and instead presents a blank screen.

Any suggestions on what configuration is needed on App Studio that I may have overlooked?

All that is needed is a standalone App on Teams to show a website with within the Teams environment.