Don't. Buying a card is risky. The problem with buying a card is that there is no guarantee that the seller is trustworthy, and there will be fraudulent acts, such as cheating you, or stealing your personal information. In addition, there are some risks in using alternative training services. For example, the game official will regard it as a violation and take penalties such as titles. Substitute training service usually refers to playing games for you through others to help you improve your game level and get items or achievements in the game.