As I mentioned in this post – Scooters, Scooters Everywhere – September 27, 2019, I found a few articles on the history of motorized scooters. They have been around since 1915: https://en.wikipedia.org/wiki/Autoped although they fell out of favor early on and stopped being made a few years later.
From the Smithsonian – The Motorized Scooter Boom That Hit a Century Before Dockless Scooters: https://www.smithsonianmag.com/history/motorized-scooter-boom-hit-century-dockless-scooters-180971989/.
Electric Scooter: Origins, History and Evolution: https://www.madcharge.com/electric-scooter-origins-history-and-evolution/
History of Electric Scooters: www.electricscootersguide.com/history-of-electric-scooters/
1915 Autopeds – first electric and gasoline motor scooters: https://www.stolenhistory.org/threads/1915-autopeds-first-electric-and-gasoline-motor-scooters.145/
This article doesn’t even cover the earliest scooter, but talks about a number of later scooters that aren’t mentioned most other places.
History of Electric Scooters: https://www.escooterbox.com/history-electric-scooters/