How do I fix my ps4 controller

So yesterday I connected my ps4 controller to my iPad via Bluetooth and it didn’t work it showed it was connected then when I switched my iPad off after like 10 mins I just turned off my Bluetooth then plugged it into my ps4 (it is off by the way) then the following morning I press the ps button my controller and it just did the flashing light 1-4 time then switched off. I’ve had this problem before so I thought I can just reset the controller then I did that by using a toothpick to press the button under l2. The controller still didn’t work I’ve watched countless videos on how to fix but none of them worked pls help

Solution 1:

If your PS4 was off when you plugged your controller in I guess it might be that the functionality of syncing your controller while you plug it in might only work when the PS4 is On (and not in sleep mode).

Does playing with the USB plugged in still works? that should trump any 'the controller is not synced to the console properly problems.