HC-12 detection by Raspberry Pi bluetooth scanner
The HC-12 is not a bluetooth device, but a 433 MHz transceiver wrapped by an MCU running who knows what firmware.
You've likely been hoodwinked by a misleading listing on an e-commerce site where these are often promoted with wording such as &quot;Replace Bluetooth Antenna&quot; where the truth is that they are at best an alternative to a bluetooth serial link which will only work if you use something like or compatible with this on both ends.
In theory if you put another on your pi, that might work, but you'd be at the mercy of whatever link semantics and assumptions are built into that MCU firmware; bluetooth and BLE serial are far from perfect either, but are at least documented and have broad hardware compatibility.
Generally speaking, one should only buy electronic modules off e-commerce sites if you can either recognize exactly what you are getting, or where you've read technical writeups by others explaining what the device really is and its capabilities/flaws as documented by those third parties make it seem useful.
That said, while there's a technical point that can be made, the question is an off-topic &quot;usage&quot; one which may end up closed.