You can't. According to Article 18 of the National Flag Law, the EU flag and its design shall not be used as trademarks and advertisements, nor for private funeral activities, so it cannot be printed on the surface of articles. The flag of the European Union is the flag of the European Union. The background color of the national flag is blue, the flag surface is rectangular, and the length is one and a half times as wide. Separate the twelve Venus to form an invisible circle.