How to add a Password input type in flutter makes the password user input is not visible , just like Android Native EditText ‘s inputtype:password?

In case you are using the TextField widget (or something that derives from this widget), you can use the obscureText property and set it to true. More details can be found here.

Additionally, consider adding these properties to prevent input suggestions because they risk revealing at least part of the password input to screen viewers.

obscureText: true,
enableSuggestions: false,
autocorrect: false,