Heat oven to 425°F. Add black bean soup to small saucepan over medium-high heat; bring soup to boil. Cook, stirring occasionally, until bean mixture thickens, about 10 minutes.
Assemble enchiladas: Spread 1 cup sauce in bottom of 9”x13” baking dish. In center of each tortilla, add 2 tbsp. black beans with sauce, 1 tbsp. shredded cheese and 1 tsp. scallions. Tightly roll tortilla and place seam-side down in baking dish. Top rolled tortillas with remaining enchilada sauce; sprinkle with remaining cheese.
Bake enchiladas until filling and sauce are hot and cheese is melted, about 10 minutes. Sprinkle with remaining scallions; serve.