Can't reset iTunes password

iTunes doesn't have a password. What are you doing when you need a password you wish to change? This? --> Change information in Apple ID - hhttps://appleid.apple.com/

What to do after [or before] you change your Apple ID email address or password - https://support.apple.com/HT204071 - "After you change your Apple ID email address or password, you might need to update your sign-in information with any Apple services you're using" including "Find My".