A minting seal is a special item that is used for minting NFTs in the Trading Post building in Medieval Empires. 1 minting seal is used to mint 1 NFT. You can view your available minting seals in the 'Other' tab in your Inventory. 

You can purchase Minting Seals from the in-game marketplace, under the 'Items' tab. 

Players will also be able to get minting seals through Daily Missions and Weekly Events in the game.