Advice please

My 19 month old boy will go down for naps absolutely fine in the day, I’ll do the same routine as bedtime. Read a book, breastfeed, white noise machine on and then put him in the cot. He’ll have no problem going in the cot or when I walk out the room. He’ll then play with his teddies and eventually go to sleep probably about 10 mins later. At nighttime the only difference is the room is completely dark. He will cry and not be able to settle when he’s in the cot, like he can in the day? Is it worth getting a nightlight? Any suggestions, does a nightlight disturb their sleep?