Expect to chase them in the first few nights till they get used to it. You may need 2 people initially.
Ensure there is a perch higher than the nest boxes in the shed. Once locked in - they will nest on it. The perch I have runs the width of the shed inside and is approximately 4 inches wide. It is above the nest boxes at a height of about 4-5ft. When I lock my hens up after dark, they are inside, all resting / sleeping on this perch. Every one of them.
It needs to be wide enough so when the hens rest - their body covers their feet. This is very important for cold nights of low temperatures.