Your eSIM connects to Movistar, also known as Telefonica Argentina. It is one of the three big carriers in the country, alongside Claro and Personal. Movistar has wide 4G LTE coverage across cities and most populated areas, plus early 5G in parts of Buenos Aires.
You do not need to pick a network or change any setting. When you land, your phone finds Movistar on its own and you are online. There is no SIM card to buy at the airport and no Spanish paperwork to fill out.