Most pediatricians suggest waiting until your little one reaches 9 to 12...

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

Most pediatricians suggest waiting until your little one reaches 9 to 12 months. Before you head out, confirm your baby maintains strong head and neck control to support a helmet. If your baby sits upright without assistance, they are likely ready