Buying BTC with Strike

I have 2 questions regarding buying BTC with Strike:

1) I am EU citizen currently living in Mauritius, and from here I am unable to download the app on my phone (it says it's not available in this region). If I would use VPN on my phone and mask my location to country of residence in EU, would that work? Also is there a list of supported European countries, I couldn't find the list anywhere?

2) When you buy BTC via Strike, where is this BTC coming from? Does Strike has its own stash and they are selling it, or do they 'source' it from other centralised exchanges or how does it work?