There's your probable cause right there.
College students have been field sobriet'd on those damned Lime and Bird scooters, found they exceeded the legal limit, and then were found guilty for DUI. And unlike cars and boats, these things have no license. Doesn't matter.
Indiana's laws are fucked up.
In Indiana, any self-propelled vehicle is considered a "motor vehicle" which obviously includes those scooters. I don't know if bicycles are included under the OWI laws (many states a DUI/OWI is operating any "vehicle" not any "motor vehicle."