Folding Bike Carrying Strap, Portable Nylon Lifting Strap for Bikes, Bicycle Frame Handle and Shoulder Carrying Lifter, Universal Climbing Stairs Assist for Mountain Bike

I use a folding bike carry handle and shoulder strap. Velcro the handle to the balance bike then sling the balance bike upside down on my back over my shoulder messenger bag style it’s not perfect but gets the job done. Here’s the strap I use https://www.amazon.com/CHEOTIME-Carrying-Portable-Shoulder-Universal/dp/B0GFNK2L6L