Can I buy a Paris Region <> Aéroports Orly or CDG ticket on my phone?

Yes, Paris Region <> Airports tickets (for access to Orly or Roissy Charles de Gaulle) are indeed available for purchase from the mobile applications to load them into your phone, your connected watch or a Navigo pass, provided that there are no Metro-Train-RER tickets (or old dematerialized t+ tickets) still loaded in your support. If this is the case, you must use another medium such as a Navigo Easy pass.