Wait until your child sits up and supports their own head, usually near age...

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

Wait until your child sits up and supports their own head, usually near age one. Front seats work well for toddlers, while rear seats suit older kids. Trailers offer a secure, reclined ride for the youngest. Check that helmet fit and enjoy the trip.