The amount of HNT tokens you can earn as a Helium miner depends on various factors, such as the number of challenges completed, the number of witnesses involved, the amount of data transferred, and the network demand. The rewards are also halved every two years to control the inflation of HNT tokens. According to [the official website] of Helium, the average monthly earnings of a Helium miner in April 2023 were $1,050.