HELP 2013 Prius v parking brake stuck

Gfs 2013 Prius v 60,000 miles she never used the parking break. I found out how to use it yesterday morning . It wasn’t til late evening when we got home (we park on a 30 ish degree hill in reverse) with the parking break engaged. An hour later we try to head out again but the car is stuck. The parking break light came off though. But it appears the back right wheel is locked. Tried pumping the e brake on land off no luck. Tried rolling the car back and forth slightly to see if it might just come loose. Nothing. The car barely moves when We tried giving it some gas. didn’t force it cause we’re scared to break something. Any advice helps please and thank you .