[Dmitry at Pelican Parts]

Hello and welcome to the forum! This is what google turned up:

Press the 'PHONE' button below the PCM screen. Then, touch 'SET PHONE' > 'Bluetooth Settings' > 'New device' > 'iPhone'. Select 'PCM' from the search list. Enter any four-digit code.¹⁾ Enter the code again and confirm with 'OK'. iOS® device and PCM are now connected.