Hello! Thank you for your question. I will be assisting you today.
I'm sorry about the issue. What kind of password XXXXX XXXXX such as Wi-Fi/wireless password, or Amazon account password, or device passcode, etc.? Do you mean the kindle is not working at all right now?
Have you tried this: if you have any cover on the kindle, please remove it for now. Then press & hold (or slide & hold) the power on/off button/switch on the kindle for about 45 seconds, then turn it back on and check.