Sorry, not a fan of anchovies. Substitution suggestions?

A small amount of Worstershire sauce (about 1 TBSP at the most.)

Yes to what 702551 and AJ have said.
Or find another salt/umami boost.
Start with a small amount (like a teaspoon for the whole recipe) of one of these:
• Pickles (other than the capers)
• Fermented sauces (miso, etc)
• Deli meat (chopped fine)
• Heat (chile in some format)

Do you like capers? Those would be a nice addition, as would a few chopped olives - but only high quality ones. I haven't tried this recipe but, especially if the cherry tomatoes are sweet (as the ones from my garden always seem to be), this dish seems just to be begging for something to brighten up the flavors. Capers or olives, especially if you add a bit of brine, would both do the trick. ;o)

The primary function of the anchovies is for umami not salt.

Just leave them out. Note that the recipe author says in the headnote to leave them out if you want this to be vegetarian.

Other substitutions would be oyster sauce or other dried fishes (reconstituted in a little water or stock). Or you could even sprinkle in a little MSG. All of those are available at Asian grocery stores. You could even add a little Worcestershire sauce; Lea & Perrins actually contains anchovies as an ingredient but doesn't taste like it.

Or make no substitution. You'll just have less umami.

Your call.