plates.js

const AVAILABLE_LETTERS = [
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
    'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
];
const CURRENT_STATE = [0, 0, 0, 0, 0, 0, 0];
const PLATES = [];

const incrementCurrent = () => {
    CURRENT_STATE[CURRENT_STATE.length - 1]++;

    if (CURRENT_STATE[6] > 9) {
        CURRENT_STATE[5]++;
        CURRENT_STATE[6] = 0;
    }

    if (CURRENT_STATE[5] > 9) {
        CURRENT_STATE[4]++;
        CURRENT_STATE[5] = 0;
    }

    if (CURRENT_STATE[4] > 9) {
        CURRENT_STATE[3]++;
        CURRENT_STATE[4] = 0;
    }

    if (CURRENT_STATE[3] > AVAILABLE_LETTERS.length - 1) {
        CURRENT_STATE[2]++;
        CURRENT_STATE[3] = 0;
    }

    if (CURRENT_STATE[2] > AVAILABLE_LETTERS.length - 1) {
        CURRENT_STATE[1]++;
        CURRENT_STATE[2] = 0;
    }

    if (CURRENT_STATE[1] > AVAILABLE_LETTERS.length - 1) {
        CURRENT_STATE[0]++;
        CURRENT_STATE[1] = 0;
    }

    return CURRENT_STATE[0] <= 9;


};

const generatePlates = () => {
    while (incrementCurrent()) {
        console.log(`${CURRENT_STATE[0]}${AVAILABLE_LETTERS[CURRENT_STATE[1]]}${AVAILABLE_LETTERS[CURRENT_STATE[2]]}${AVAILABLE_LETTERS[CURRENT_STATE[3]]}${CURRENT_STATE[4]}${CURRENT_STATE[5]}${CURRENT_STATE[6]}`)
    }
};

generatePlates();

function generatePlate(length = 8) {
    let text = "";
    let possible = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    for (let i = 0; i < length; i++)
        text += possible.charAt(Math.floor(Math.random() * possible.length));
    return text;
};

function generatePlate(length = 8) {
    let text = "";
    let possible = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    for (let i = 0; i < length; i++)
        text += possible.charAt(Math.floor(Math.random() * possible.length));
    return text;
};

While the idea behind that is sound, it also fails to meet the requirements of the project. Your solution will generate a randomized plate, which is not what the project called for. The project called for the generation of all license plates that conforms to the CA DMV pattern.