Firefox: Remember new passwords without prompting

"Hacking Firefox to Always Auto Save Password Without Showing Notification Bar:

Close Firefox
Edit nsLoginManagerPrompter.js with notepad which is normally located in C:\Program Files\Mozilla Firefox\components\
Replace the entire lines 642 to 711 with the code below:

var pwmgr = this._pwmgr;
pwmgr.addLogin(aLogin);

Now whenever you login to any website, Firefox will auto save the site, username and password to the login manager WITHOUT showing the notification bar.

Note: even when you enter the wrong username or password, it will still be saved.

Source"

"It looks like this site here has the answer you are looking for here.

It states that you must have all instances of Firefox closed, navigate to the ""C:\Program Files\Mozilla Firefox\components\"" directory, open up nsLoginManager.js and comment out lines 112 and 121."

"I know this is ancient question but here is a guide for Firefox 71.0.

First of all we need to extract archive which contains all the password manager JavaScript. It is omni.ja in Firefox main installation directory. To find out how to extract and pack it back look at the official documentation here (you can use latest version of 7-zip to do it).

Once you have it extracted look at these functions and edit them (line number, name). You need basic knowledge of JavaScript for that.

modules/LoginManagerPrompter.jsm
1426 _showSaveLoginDialog
946 promptToSavePassword
422 promptUsernameAndPassword
552 promptPassword
669 promptAuth

modules/LoginManagerParent.jsm
571 async onFormSubmit

When you edit these functions you can repack the file back with command mentioned in documentation (repacking it other way might not work, zip command is for Unix only):

zip -qr9XD omni.ja *

Now every password will get saved even when Firefox is set to ignore certain site."