unable to understand how it works, sometimes appears when making a new sign in sometimes don't

Simple and sleek. How every app should be

The best

This is a complete add-on for password security. I've been using Proton products for years, and none have ever let me down. They haven't sold telemetry data to third parties. The Firefox add-on hasn't shown any incompatibility issues; on the contrary, it works flawlessly and hasn't given any errors.