Freezer door not sealing

My freezer is thawing. The door no longer makes the swooshing sound when it seals and it seams not to close tight. Help! I’m thawing. What setting should my t-stat be at?
Thanks

Try cleaning the door seal the coating it with vasiline lightly. If this dosen’t help and door still is not sealing you will have to replace the seal. If ite temp was ok before the seal problem don’t change it