Wait until your baby is one year old and sits up unassisted. They must hold...

https://www./parenting/when-can-a-baby-go-in-a-bike-seat-an-age-by-age-guide/

Wait until your baby is one year old and sits up unassisted. They must hold their head steady under the weight of a helmet. Pick front seats for engagement, rear seats for better balance, or trailers for napping