Wait until your baby reaches twelve months to ensure their neck muscles support...

https://www.fastbookmarks.win/wait-until-your-baby-turns-one-they-need-steady-head-control-and-the-ability

Wait until your baby reaches twelve months to ensure their neck muscles support a helmet. Look for independent sitting before riding. Choose front-mounted seats for engagement, rear seats for stability, or trailers for the safest, comfiest nap-time rides.