The national airline Aerolineas Argentinas offers the most flights from Buenos Aires to Salta, in addition to thrice weekly connections from Salta to Iguazu, Mendoza, Cordoba and Rosario. Apart from Aerolineas Argentinas, JetSmart and FlyBondi also operate daily flights between BA and Salta. Jetsmart also has three connections a week to Neuquen in northern Patagonia and twice weekly Iguazu. Here are the links you can visit: https://www.aerolineas.com.ar/
https://jetsmart.com/ar/es/
https://flybondi.com/ar