Grilled Zucchini and Ricotta Flatbread

Name: Grilled Zucchini and Ricotta Flatbread
Ingredients: 2 tablespoons olive oil, plus more for grill; 2 large zucchini (about 1 lb.), sliced lengthwise ¼” thick; 1 bunch scallions, trimmed (about 6 oz.); Kosher salt, freshly ground black pepper; 1 lemon, halved; 1 pound prepared pizza dough, room temperature, divided in half; 1 garlic clove, halved; 6 ounces fresh whole milk ricotta; 1 ounce grated asiago cheese or pecorino; Crushed red pepper flakes and torn fresh basil leaves, for serving