Let us recap the problem. The lead is the Jack of hearts.
Unlike the first variation (2020 Declarer Play #2), you cannot duck to rectify the count because East will win the trick and give his partner a heart ruff. So you have to envision a more complex ending, that will take advantage of your two possible menaces: the establishment of the 4th heart, and the establishment of the Jack of diamonds.
However, since you could not rectify the count, your plan must include the fact that a trick will be lost eventually (you have only 11 top tricks). Since you are not planning on using your clubs as a menace (at least initially -- you may change your mind later if it seems advisable), it is better if you can take away as many clubs as you can, to prevent the opponents from having winners after you run your tricks.
So, with this vague plan in mind, you can start by winning the heart trick, playing a club to the Ace, trump to dummy, club ruff, trump to dummy, club ruff. Everybody followed suit to the clubs, and you are looking at this ending:
You can project that East now has 3 hearts and KQ of diamonds (and some other cards). If you cash 2 trumps, pitching 2 diamonds from dummy (you will need that club, as you will see), what can East keep? He will keep 5 cards. 3 of them will have to be hearts (else you can duck a heart), so he will have to keep the KQ of diamonds tight, pitching all other cards (including any clubs).
If clubs were originally 4-4 (i.e., if West has only one club winner at this stage), you can play a heart to dummy, to reach this ending:
You are in dummy. If you play a club, East now has 2 losing options. If he discards a heart, you can ruff the club, and lead a heart -- dummy will be established. He will probably pitch a diamond, then. Now your Jack of diamonds is high... but the diamonds are blocked. If you ruff this trick, you will lose the last 2 hearts in dummy.
However, if you discard a heart in this club trick... West has only diamonds in his hand! He is forced to unblock the suit for you, and you make the last 3 tricks.
For this ending to work, West cannot have an extra club winner in this ending. But it is your best shot, so this is the correct play. You will need West to have at most 4 clubs originally.