Firstly, dummies aren't kept in for the night, they aren't meant to and don't need to. They are needed for more than a minute though.
When anyone falls into a deep sleep, all their muscles relax. This includes the muscles around the mouth and jaw. The dummy is used just for when going to sleep. Once into the deep sleep it will naturally drop out as muscles relax around the mouth and jaw.
So the expectation for a baby using a dummy would be that they only need it for the time it takes to go to sleep. For my DD that would be 10 minutes at most, sometimes just a few minutes to drop to sleep. Dummy is done with then.
It sometimes takes some perseverance until baby 'gets' that they need to suck a dummy - until then it just sits in their mouth doing nothing. Gently holding it the babys mouth can help. Or tapping the dummy when it is in his mouth.
Try giving dummy in different positions - like while holding baby in BF position. Before baby has accepted a dummy avoid giving it when baby is distressed - so not when over tired or hungry. Always feed first with a newborn, most cries are to go with hunger so giving a dummy will just create frustration.
There are lots of shapes of dummy you can get. I have always favoured the cherry soother shape but others swear by MAM dummies. See what works for you.