Ahh, I see. OK, firstly, Blynk works either “serverless” (as far as sharing data between App and Hardware) using BT/BLE between phone/tablet and hardware device:
App ← BLE/BT → Hardware
Or as “normal”:
App ← internet/network → Server ← internet/network → Hardware
But not “mixing” or using phone as a gateway (at least when using the BT/BLE link).[quote=“acca, post:3, topic:14510”]
As far as I understood, it is still not possible to work with Blynk and BT/BLE offline, right?
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The phone still needs to be online (or at least connected via WiFi to a Local Server), but that is in order to access your account and your projects (which are actually stored on the server, not the phone)… So Yes, internet is required with Cloud Server, but you could make an “off-line” portable setup with a RPi ZeroW as both a Local Server and WiFi AP - search for that here - Setup PI ZERO W as ultra portable server and AP (tutorial) updated to 2022 :)
I am afraid that is out of my experiential range to fully answer… but the plausible answer is maybe 
but that might take some good programming and BT protocol knowledge.
Currently BT/BLE seems in Beta and possibly a bit on the back burner, but perhaps post a hardware support request into the Developer’s GitHub page?