Please proceed as follows to change your App Password:

'Menu' > 'Settings' > 'Security' > 'App Password' > 'tipe in your current App Password' > 'Go on' > 'tipe in your new App Password'

Please note: The App Password has to have at least 6 characters und you should be the only who knows it. To increase the security of the App Password choose capital and small letters as well as numbers and special characters.