With the baby's chin lifted and leading the latch, nose in line with your nipple, bring the baby to your breast. (womenandinfants.org)
To latch a baby on well in any position you will need their nose in line with your nipple. (breastfeeding-babies.com)
Good positioning for an asymmetric latch means that your baby's upper lip is in line with your nipple so they have to tilt their head back a little to latch on, thus opening their mouth wider. (breastfeeding-babies.com)