Cannot open Blheli32 Pixhawk4

Cant seem to use Blheli. Error: Com 3 not available. Is Blheli compatible with Qgroundcontrol? Tried many variations but so far no success. Using 4 Tekko 32 esc with Dshot 1200 set up.

PX4 cannot be used as a passthrough for BlHeli32.

It seems you can setup Dshot on Pixhawk-4 in Qground, but you would not be able to use it even if yo are connected to the AUX. Also, BLHeli32 will not work. I had to install Ardupilot on Pixhawk-4 and use the Passthru, but it still would NOT see the ESC, but it was connecting. Although I have PM07 PDB in the middle, but it should not matter. Here are the settings that I had. Let me know if you had any luck with it:

SERVO_BLH_AUTO 1 0:Disabled 1:Enabled If set to 1 this auto-enables BLHeli pass-thru support for all multicopter motors
SERVO_BLH_DEBUG 1 0:Disabled 1:Enabled When set to 1 this enabled verbose debugging output over MAVLink when the blheli protocol is active. This can be used to diagnose failures.
SERVO_BLH_MASK 1 Enable of BLHeli pass-thru servo protocol support to specific channels. This mask is in addition to motors enabled using SERVO_BLH_AUTO (if any)
SERVO_BLH_OTYPE 7 0:None 1:OneShot 2:OneShot125 3:Brushed 4:DShot150 5:DShot300 6:DShot600 7:DShot1200 When set to a non-zero value this overrides the output type for the output channels given by SERVO_BLH_MASK. This can be used to enable DShot on outputs that are not part of the multicopter motors group.
SERVO_BLH_POLES 14 1 127 This allows calculation of true RPM from ESC’s eRPM. The default is 14.
SERVO_BLH_PORT 0 0:Console 1:Serial1 2:Serial2 3:Serial3 4:Serial4 5:Serial5 This sets the serial port to use for blheli pass-thru
SERVO_BLH_REMASK 0 Mask of channels which are reversible. This is used for ESCs which have been configured in ‘3D’ mode, allowing for the motor to spin in either direction
SERVO_BLH_TEST 0 0:Disabled 1:TestMotor1 2:TestMotor2 3:TestMotor3 4:TestMotor4 5:TestMotor5 6:TestMotor6 7:TestMotor7 8:TestMotor8 Setting SERVO_BLH_TEST to a motor number enables an internal test of the BLHeli ESC protocol to the corresponding ESC. The debug output is displayed on the USB console.
SERVO_BLH_TMOUT 0 s 0 300 This sets the inactivity timeout for the BLHeli protocol in seconds. If no packets are received in this time normal MAVLink operations are resumed. A value of 0 means no timeout
SERVO_BLH_TRATE 10 Hz 0 500 This sets the rate in Hz for requesting telemetry from ESCs. It is the rate per ESC. Setting to zero disables telemetry requests