Pacifier falling out at night.

My daughter is 3 and a half months old and she can’t sleep without a pacifier. Which I don’t mind. But she’ll fall asleep and as soon as her Paci falls out of her mouth she’s moving around fussing with her mouth open trying to find it and if I don’t hurry and get it back to her she’ll wake completely up and be up for hours.

When will she be able to get the pacifier herself to put it back in. Or how can I help make her sleep fine without the pacifier in her mouth???