Depending on whether your child has reached the min height (find at the Velcro near the bum area). My baby is short so I can only start using when she’s 3-4mo.
I tried when she’s a month old but didn’t know there was a min height so she was crying really badly but when I tried when she’s 3mo (someone told me to check the height) and she fell asleep within 2 mins. (I’m using Ergobaby Omni 360)