For both CHAdeMO & CCS, please check:
Is the charging session still active/EV still charging? If so, you will need to stop the session first before being able to unplug your vehicle via the Mobile App or by swiping your RFID fob on the charging station.
First, confirm LED light on the handset is not on. Then press the release mechanism on handset until you hear a click to release from the vehicle or for (ABB stations) push the release button forward until the green OK is covered. Sometimes you need to jiggle the handset to remove it from the vehicle.
Your car may be locked, which also locks the plug:
Check: Is the car locked? If so, unlock your vehicle and try again.
Tesla Model 3 – Unlock from Tesla app or unlock charging port on the screen in the vehicle.
Check vehicle remote for charging port unlock button.
Refer to Vehicle Manual.