The US military cannot be seen operating out here.
The series opens with Sam helping the Air Force stop a terrorist threat to one of their planes near the Tunisia/Libya border
The majority of this exciting sequence appear to be a digital creation of a generic Tunisian canyon, and not one in specific. The canyon style created is very reminiscent of the famous canyons of the country, including the Star Wars canyon, Sidi Bouhlel. This canyon is located near the town of Tozeur in Tunisia.
The in-universe map places the action further southeast from Tozeur, very close to the eastern border with Libya, just North of Remada, in a canyon that ends at the Libyan border.
(The Falcon and The Winter Soldier S01E01, 2021)