Can someone help me identify this part and help me get this Prius back on the road.

So a little back story. Got this car off Copart, very excited as it is the first car that I've every bought. Have had hand me downs since I started driving. Never had issues with that, but to have bought my first first car, am very excited.

After removing rear bumper and rear splash shield there is this black box near the driver rear wheel area. Can anyone identify it? Does anyone know what it does? It had water in it but I live in Texas and it is hurricane season.

Also have never worked on a car before so wish me luck, whether it takes 6 months, plan to get this up and running, hopefully for another 150K...

 

Thanks! Car did not start when delivered but lights did come on with portable jumper. After charging battery the car was able to start. Accident was 6/2021 so didnt sit too long. Was able to find part on ebay then lead back to a post here with Mendel. So i found it, vapor canister.

You got it. Hard to identify something broken but not also something commonly covered on auto repair videos.