The charge port should be unlocked when you unlock the vehicle through the app. However, sometimes this may not be the case, if the vehicles electric lock mode is enabled.

To quickly release the cable, press the unlock button on the drivers side door. You should then be able to pull out the charging cable.

Deactivating the electric lock mode should prevent any issues with pulling out the charging cable in the future. This will need to be done on the vehicle's infotainment screen:

Car Widget > New Energy > Charging Settings > Deactivate