Wait until your baby sits independently and holds their head strong, usually...

https://gunnerawsh736.cavandoragh.org/why-does-my-child-bike-seat-squeak-and-rattle-the-whole-ride

Wait until your baby sits independently and holds their head strong, usually around nine months. Front seats suit smaller babies, while rear seats fit toddlers. Trailers offer the most stable ride. Always prioritize neck strength for helmet safety