Kaspersky Password Manager (KPM). It remembers the complex passwords so you don't have to. It works like a silent, very loyal butler living inside your Firefox browser.
Now go forth. Install the extension. Generate a password that looks like a cat walked on a keyboard. And never type a password manually again. 🦊🔐 Kaspersky Password Manager Extension Firefox
If you lose your Master Password, your data is gone forever. Kaspersky cannot reset it. That is a feature, not a bug. Write it down on a piece of paper and hide it in your sock drawer. Seriously. Kaspersky Password Manager (KPM)