My 3 year old doesn't know how to sleep

We've been giving him a quarter of a melatonin but want to stop.

We turn off the TV an hour before bedtime but he just lays in his bed flipping around and laughing to himself until he passes out after 2 hours.

We have a set and predictable routing that includes bedtime stories but as soon as we lay down his active switch flips

We're at a loss of what to do.

He does not take naps and is active during the day.

He watches TV but doesn't have access to an iPad or phone.

Hes speech delayed due to a hearing issue so sometimes it's hard to know what he actually understands.