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

https://noon-wiki.win/index.php/Can_a_Baby_Sleep_in_a_Bike_Seat%3F_A_Shop_Expert%E2%80%99s_Guide_to_Nap_Safety_Biking

Wait until your baby sits independently and holds their head steady, usually by age one. Front seats boost interaction, rear mounts offer classic stability, and trailers provide the safest, comfiest ride for little ones