Hi Chiqui!
What’s his personality like? For our (very strong-willed and independent) daughter, we had to remove ourselves from the process entirely. She didn’t want help on the big toilet, didn’t want help washing her hands, didn’t want help being prompted or reminded when to go. So one day, a friend brought over her mini-version potty and I put it in our bathroom, saying “This is yours. You’re totally in charge of your pee and poop. Let me know if you need me.”
She never went back to diapers afterward. :)
Our son, however, is totally different! He likes us to cheer for him every time he keeps his diaper dry, likes us to help him with every aspect imaginable. (For the record, he’s the same age as your son and still hit-or-miss.) I’d say reintroduce gently when he’s 3! He’ll get it soon enough. :)