Hey, just designed a 3D printable adapter for the 1st gen Kids ride Shotgun, which enables mounting it to some E-bikes.
My children loves it. If it helps you out, here is the link for Makerworld:
https://makerworld.com/models/1696718
And for Printables:
https://www.printables.com/model/1383506-kids-ride-shotgan-e-bike-adapter
by Key-Ladder6386