The rear door hatch is locked and won't open. The power locks sounds like they can't open in the locked position.
If the door latch lock cylinder is not unlocking the latch, then the inside door panel would have to be removed in order to access the latch and try and open it; this would be the only way to open the door, if the lock is stuck. I would recommend having a mechanic, such as one from YourMechanic, inspect your power door locks, and recommend the best path to repair.
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