RaceChrono Pro download link:App Store “RaceChrono Pro” (apple.com)

NOTE:
Just enable Bluetooth settings on your iOS device.
DO NOT Need to connect Bluetooth Name on iOS device.
Then connect the Bluetooth device name in the OBD app setting.

Step1:
Click the Settings button in the upper right corner.





Step2:
Click on "Add OBD-II reader"





Step3:
Click on "Vgate vLinker/iCar BLE/BT4.0"





Step4:
Select OBD-II reader "vLinker FD-IOS".





Step5:
Return to home page after selecting OBD II device.





Step6:
Click on "START"





Step7:
Connected successfully.