TK 8180, has a serial port on the back. Radio settings have to be changed to utilize the blue tooth which plugs into the 25 pin serial on the back of the radio,
Most of the pins on the DB-25 are already assigned for audio out, mic in, and power. You'll need to assign one of the IO ports for PTT. You will need to know which pin on the DB25 the bluetooth adapter is looking for it.
MI2 = Pin 6 (this is the Microphone level input TO the radio FROM the bluetooth connector
ME = Pin 25 (Microphone Ground)
AFO = Pin 17 (Filtered Audio Output FROM the radio TO the bluetooth device)
Ground = Pin 7
The PTT needs to be assigned to the correct pin to match the bluetooth adapter. That'll depend on how its wired and the manufacturer should tell you this. You'll set this under the "Extended Function" tab, specifically under "AUX".
You will then need to go into the "Modulation Line" tab and set up the MI2 (rear mic) setup.
Sent MI2 line to "Connect"
That should get you started. There may be some other settings to adjust, like the external mic gain, but get it all functioning first before adjusting that.