Combine all the teriyaki sauce ingredients in a small saucepan over medium-high heat. Stir until the sugar dissolves, then bring to a boil. Reduce the heat slightly and simmer, stirring frequently, until glossy and thick enough to coat the back of a spoon.

Pour the teriyaki glaze into a wide, shallow container and leave it uncovered. Freeze for 5 minutes or until completely cooled. Do not add hot glaze to raw salmon.

Pat the salmon filets completely dry with paper towels, then cut each filet widthwise into 2 equal pieces. Add the salmon to the cooled teriyaki glaze and coat evenly. Marinate at room temperature for 15 minutes.

Place the salmon filets skin-side down in a single layer in the air fryer basket, leaving space between each piece. Generously brush the tops with the remaining teriyaki glaze.

Air fry at 400°F for 6-8 minutes, checking at the 6-minute mark to prevent overcooking. Insert a digital meat thermometer into the thickest part of each filet and remove the salmon once it reaches 145°F.

Transfer the salmon to a serving plate and garnish with green onions and toasted sesame seeds. Boil any remaining marinade in a clean saucepan for at least 1 minute before drizzling it over the salmon.