22 month old won't go to sleep

[2under2hudson]

We've tried everything I think. He's on one nap a day 11-11:30 husband wants to stop this too but I think he's too little but he's awake until 9pm!
We do tea bath and bed but he's wide awake and shows no signs of sleep.

Do you mean he literally naps for 30 mins 11-11:30, or he starts a nap between those times?
What time is he up in the morning?
What time is he going down in the cot to achieve a sleep time of 9pm?