Have physical activity in the mornings. So the child gets out their yah-yah's.
Come home.
Wind-down.
Eat lunch. I mean like before noon.
Keep things quiet and calm. No horse-play. Otherwise the child will be too keyed up to wind-down and nap.
Kids this age NEED to wind-down first... before naps or bedtime.
Verbally prompt him. Tell him: after lunch, it is nap time.
After lunch wind-down. Make everything quiet and boring. Read a book. Make things dark.
The child needs to 'transition' to naps.
At this age, sleep tweaks happen. It is common.
Being over-tired also makes it harder for a child to sleep. And some kids actually get more 'hyper' when they are over-tired. My son is like that.
But he is napping NOW in fact.
It is a daily routine.
My son knows the routine.
It is the same everyday.
My son is 5.
He has always napped. We've always had the same routine, every afternoon.
A kid, needs to segue to naps and wind-down first.
Also, my son will not nap, if he still hadn't pooped. So after eating, I wait for him to poop. Then I know he can nap.
If you know your son still needs naps, which at this age many still do... then you keep to a routine. But, for me at least, it takes about 1 hour to wind-down my kids, before nap. It is a process.
A kid doesn't nod off as soon as they hit the pillow.
And you NEED to verbally cue the child, tell them what is coming up.
AND when my kids were younger, I told them that it is ALSO MOMMY'S nap time too. We ALL do that or have quiet time.
I sit in my son's room. Read a magazine. I do not interact with him. I don't even look at him. He lays down and lolls about. I verbally cue him in a monotonous boring voice. And once he starts to yawn, I know he will fall asleep. Then I leave.
I never lock my kids in their room to nap or at bedtime.
Kids at 2 years old, DO NOT HAVE, self-management. They do not have, total self-regulation.
You need to help them.