You’ll need to access it from the rear passenger area, which will involve moving the seat forward and removing the panel in the floor beneath the seat. (As you remove it, be careful of the clips that hold it in place.)
Once you’ve removed the floor panel, you’ll have access to the battery.
Once you’ve downloaded the app, it only takes about 45 seconds to get started. When all is said and done, the average driver who ends up making a switch saves over $800 per year on their car insurance!