I have problems

Turn on the headlights. Are they bright? If not, that is a good sign the 12V battery needs to be replaced or at minimum charged.

If you decide the battery needs to be replaced, you can open the hatch by crawling into the hatch area, removing the folding hatch floor, then removing the small access panel in the black plastic tray above the spare tire, facing the rear of the vehicle. Then you will have access to the mechanical hatch release which is a shiny lever. Move that lever and apply upwards pressure on the hatch to open.

 

Anytime a Prius starts acting stupid check the 12 battery.

 

I'd pop the hood and attach 12v power to the jump point before crawling through the car to pop the hatch.

 

Yes if the 12V battery is charged.

 

One possibility is a blown AM2 fuse caused by a shorted inverter coolant pump. The fuse box is under the hood next to the drivers fender.

 

It sounds like you are saying that NOTHING electrical works.....including the dome lights ??

It is a bit unusual for a 12 V battery to go totally DEAD all at once but loose battery cables can cause that.

Then.....if it still has the original factory battery, you are WAY overdue for a new one, even if it turns out that is not the current problem.

 

12 volt dead pretty common. Usually caused by leaving the interior overhead light on all night or the hatch is not closed and there’s a light back there. There’s a hatch light switch in the back on the side wall.
I keep mine turned off.
Have to crawl in the back and pull the mechanical emergency hatch release lever.
Replace the 12 volt battery. Don’t bother having it tested usually when it’s so
Perfectly discharged by a light bulb it causes sulphation and will be troublesome and leave you stranded.

Replace the 12 volt and pay attention to the lights when leaving the car overnight.