On Android, this game does its resolution and measurements upon starting the game, so once its started... those measurements won't change.
So trying to rotate the game after its been loaded already will just make it sideways.
Instead, what you have to do is ensure that the game is opened sidways.
For this, we typically use a Screen Rotation app like: https://play.google.com/store/apps/details?id=org.crape.rotationcontrol&hl=en_US&gl=US
Apps like this can "force" your device to be a specific orientation. This way, when you open the game, landscape will be used for the measurements.
A contact email is required to put an app up on google play I believe. I just found that on the apps webpage: