Sheet Pan Steak Fajitas

Name: Sheet Pan Steak Fajitas
Ingredients: 1 pound skirt steak (or top sirloin or flank steak); 1 large red onion; 3 bell peppers (any color(s) of your choice); 3 tablespoons avocado oil (divided); 1 tablespoon fajita seasoning (or more, if desired); 2 teaspoons chili powder; 1½ teaspoons cumin; 1 teaspoon sea salt; ¼ teaspoon oregano; ½ teaspoons garlic powder; ½ teaspoon onion powder; ¼ teaspoon paprika; ⅛ teaspoon cayenne (optional); lime wedges; butter lettuce leaves ((for lettuce wraps)); flour tortillas (or low carb tortillas)