Faturar means 'to make a profit' or 'to earn', often in a business context. While it's a common verb, its use in this song is particularly striking and ironic.
In "Que País É Este", Legião Urbana uses faturar to highlight the cynical and corrupt view of some Brazilians who believe the country will only get rich by exploiting its own people and resources, even to the point of selling "the souls of our indigenous people in an auction." This dark and critical use of the word makes it very memorable and impactful.
Legião Urbana's "Que País É Este" is a state-of-the-nation inventory, written by Renato Russo as Brazil came out of military rule in the late 1980s. Each verse names a place — the favelas, the Senado (Senate), the Amazon, Baixada Fluminense — and finds the same rot waiting in it: "Ninguém respeita a Constituição / Mas todos acreditam no futuro da nação" (Nobody respects the Constitution / But everyone believes in the nation's future). The refrain "Que país é esse?" (What country is this?) repeats until it stops sounding like a question and starts sounding like a verdict.
The closing verse turns the irony explicit: Brazil will get rich, the song says, "Quando vendermos todas as almas / Dos nossos índios num leilão" (When we sell all the souls / of our indigenous people at auction). No resolution follows — just one more region added to the list.