You can go to "Events" and click "Monthly Rewards" to view the monthly rewards that can be collected. The monthly rewards must reach the minimum recharge of each level to receive the corresponding rewards. The more you recharge, the higher the level, and the higher the reward.

The Monthly Rewards are distributed to the mailbox on the 1st, 10th, and 20th of each month.

Recharge Levels: There are 12 levels, determined by the amount recharged.
LV Upgrade Rewards: Receive rewards upon upgrading; higher levels receive more monthly rewards and lv upgrade rewards.
Distribution Time: Monthly rewards are distributed to the mailbox on the 1st, 10th, and 20th of each month.
Reset Rules: Reward levels are reset to 0 at the end of each month.