While purchasing the first ticket, you can mark the Return button, or after purchasing one-way, you can re-enter the system and purchase the return tickets by examining the reverse route sign with the reverse route sign.
When you search for flights between Belem and Manaus, all active companies and flight times on the date you entered are listed. You can find the cheapest flight tickets by sorting this list by price.
The most frequently used airline companies from Belem to Manaus are generally
Azul Linhas Aereas Brasileiras,
TAP Portugal,
Tam Linhas Aereas,
Copa Airlines
are companies.