The steps to fill in the game identifier are as follows:

In the game "Battlefield 5", when starting the game and creating a character, you will be asked to fill in the EAID. You can find the EAID filling box in the character creation interface, and then fill in the correct EAID. After filling out, click "Next" to continue the role creation process.

When filling in the EAID of "Battlefield 5", you need to comply with certain rules. EAID is a unique identifier used for authentication and needs to consist of 8 characters, including letters and numbers.