random_password generator in javascript

index.js

const random_password = (len=64) => {
    let chars='abcdefghijklmnopqrstuvwxyz123456789-_=+`~:;>,.<}{[]|)(*&^%$#@!';
    let password = '';
    while(password.length < len) {
        password+= chars.charAt(Math.floor((Math.random() * chars.length) + 1) % chars.length);
    }
    return password;
};