New iPhone X "Green line of death" but no proof of purchase.

Warranty restriction! - http://www.apple.com/legal/warranty/products/ios-warranty-document-us.html - "IMPORTANT RESTRICTION FOR iPHONE, iPAD AND APPLE TV SERVICE. Apple may restrict warranty service for iPhone, iPad and Apple TV to the country where Apple or its Authorized Distributors originally sold the device." <-- The warranty does not outright deny warranty coverage in other countries but there are many limitations to the effect they almost certainly will refuse to do repairs under warranty or even repairs at all except where you bought it. The phone would almost certainly have to be sent to a friend in the country of purchase to handle any repair claims because Apple will not handle international shipping.

Apple Authorized Service Provider is not Apple Store, there won’t have any Genius Bar, just like a normal phone repair center, but only also got Apple Authorized.

You should always keep your receipt and the box of your phone.

Go for a shot

https://support.apple.com/repair

Also, try to visit an Apple Authorized Service Provider, you get a higher chance on not need your receipt or your box.

Of coarse that is not good enough, I can also go to google and find a iPhone box image and say that iis mine.

Next time keep a receipt and the box.

Good luck !