The OPPO r17 connects to carlifa and only shows the charging reasons as follows.
It's just that you don't have the right connection. The correct method is to connect one end of the data cable to the mobile phone and the other end to the USB interface of the car system. Then open the Settings of the phone, pull to the bottom of the Settings, see the option about the phone, and then see the version number of this option click 7 times to enter the engineering mode, and then it will successfully connect and cast the screen.