Can't open provisioning file with 3CX app on Android

[Vali_3CX]

I forgot to mention the third critical condition: the client should NOT be SIP registered in order for PnP to work. Therefore, while you're registered as extension 100, you cannot PnP for extension 101.

since what version has PNP been available?

Apart from a bug, the proper question should be "since what version has PNP no longer been available" - PnP has been available since version 1.x, roughly seven years ago