How to upgrade NFT?

Click on the button with the green arrow up on the character image:

A confirmation window will appear. The cost of raising the level is affected by the current level of the character. You can speed up the level increased by spending $USDT, more information can be found in the section "Game-Fi Elements":

🎯Game-Fi Elements

The price includes a service commission of 6%. After deducting the commission, the $USDT invested by the participants is collected in the treasury. After the victory of your Faction, the invested funds will be returned and a reward will be awarded.