I want to see my purchasing bill of iPhone X

If you bought it from Apple Online Shop, contact Apple:--> Contact – Official Apple Support

If you bought it elsewhere, contact the seller and ask for a copy of your document.

Regards

Giulio

If you didn’t save a copy of it you will have to contact the store you bought it from.

L=2 - G=0.... (no way to beat you today, but my problem is that I play away from home ;)

Maybe I’ll retire for a while 😁

Haha, nope. I'll try to survive, in this sad situation ;)