You can try a rolled up towel or foam pool noodle under the base (in the seat bight), like this:
to give it more recline. Newborns should be at 45 degrees, which is what it's supposed to be when your level indicator is in the right spot. But a newborn's head flopping forward is a major safety issue because they are not strong enough to lift their head back up. It can cut off their airway.