I want to teach English but I am from France. When I select English as my teaching language, why can't I choose France as my origin?

The option to choose a country after the teaching language selection is not to indicate where you personally are from, but rather to confirm the variation of the language depending on the accent or dialect. For example, Portuguese from Portugal has distinct differences from that of Brazil. So a tutor who has learned Portuguese from Brazil, even if they are not a native speaker and are from another country, would choose Brazil in this step.