Cut off ends of green plantains.
Carefully use your knife to score the skin of the plantain then peel off the skin.
Cut the plantain into 1 inch coins.
Toss the plantains in enough avocado oil to coat.
Line your air fryer with the plantains in a single layer.
Air fry at 400F for 5-6 minutes.
Remove plantains, then flatten with something with a flat surface (bottom of a cup, plate, bowl, or small skillet).
Toss the flatten plantains with more avocado oil and kosher salt.
Place the flatten plantains back into the air fryer in a single layer (you may have to cook in batches) and air fry for 5 minutes at 400F.
Flip the tostones and then air fry for an additional 4-5 minutes at 400F or until golden brown.
Serve tostones immediately!