At 2 years old, sleep/nap tweaks happen. The child is undergoing a ton of developmental changes. This is common.
Both my kids did that too.
Just KEEP to a daily nap routine... if he does not fall asleep to nap, then have a quiet time....
But keep to a nap routine.
It will pass.
Or what I did, is I stayed in the room, had them lie down... then I read a magazine or something, did NOT engage with them or even looked at them. Then they would settle down and fall asleep. It was temporary.
Also, make sure you have a wind-down time BEFORE nap time. Turn everything off... make it 'boring' and darken the room if possible. Have him put on his pj's too. This takes me about 1/2 hour, to wind down my kids. Both my kids still nap. My son is 3 almost 4, and my daughter is 7. My son and daughter are napping now in fact.
We have the SAME routine everyday for naps. I don't have to force it. They also are tired and need it. Or they get mega fussy and over-tired.
It is now auto-pilot in routine. They don't fight about it.
all the best,
Susan