No more FMM paper arriving in major airports

Friends arrived in Zih yesterday direct from US... Their paper FFM from the plane was not used, and they had to scan a QR code and complete an online form. They then just got a stamp with FFM duration - no paper form given back. So looks like the new system has made it here?

So it is a law to have a working cell phone in a foreign country????

Seems doubtful... I'm only relaying their experience that suggests the new system is in place at ZIH. Sorry if my word choice suggested there was only one option for how to do it -- I have no idea on those details. I would imagine that there is an alternative for someone without a mobile device or connectivity beyond deporting them.