Declarer must not ruff the ♣ lead, but instead discard a ♥ loser in his hand. This forces North to win with the J♣ and ensures a future trick with Dummy's 10♣ (which is now the highest club).
Declarer wins trick 3 in whichever suit North leads next.
Declarer, after drawing all Opponents' trumps, leads Dummy's 10♣ on which he discards his second ♥ loser.
This is the best way of making the contract (losing two ♣ tricks and one trick in ♦).

Wrong play
If Declarer instead ruffs the second trick, North will of course not play his J♣. As a consequence Dummy's 10♣ will not make a trick either.
Declarer now has to depend on the 50% chance of North holding the K♥, so that his Indirect finesse to Dummy's Q♥ is successful.
If not Declarer will lose one ♣ trick, one ♦ trick and two ♥ tricks, 4 in total and one down on his contract.