How to upload to TestFlight from Windows Box

Okay, Apple Gurus, last year Testflight had an application loader. For some reason, they have removed it. Last year, when I archived in visual studio, I got an IPA file....which is no longer there either.

I have created an Xamarin Cross Platform app, how in the world do I now get my app uploaded to test flight?
How to upload to TestFlight from Windows Box
 
 
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