Hello moms! Our son is 3 months old and has problems with nighttime sl…

Hello moms! Our son is 3 months old and has problems with nighttime sleep. Share your experience dear girls, how can we establish a routine? During the day he sleeps well, even doesn't want to wake up. Between naps, he stays awake for 1-1.5 hours. Then at 9-10 pm he falls asleep for half an hour and until 2 am we go with him, crying, capriciously wants to sleep but won't fall asleep. How can we establish nighttime sleep? And he still sleeps until 6 am at night, then all night he fidgets and sleeps. Strange...