While you can get away with a blank line in print, it’s preferred to have something to signify the break in the eBook edition. It can be a simply 3 asterisks centered (very common):
The reason for this is for the eBook, all text is reflowed to fit the screen/font of the reader used. Thus, it’s quite possible that your blank space to signify the scene break will land at the top or bottom of the screen. When this happens, the reader will most likely e miss the scene break cue.
I’d recommend you always designate scene breaks with in addition to not indenting the first paragraph in the new scene.