: Users could share their current browser tab instantly with others through the Firefox Hello communication tool.
You're referring to an older version of Mozilla Firefox, specifically version 4.5.0 or more likely 4.50.1, which seems to be a mistaken or incorrectly stated version. Mozilla Firefox versions are typically denoted with three numbers (e.g., major.minor.patch), and reaching a version as high as 450 is not feasible for a web browser version number. mozilla firefox 450 1 old version
Do not enter your passwords, credit cards, or personal data into any browser version below Firefox 78 (released 2020). The "old version" you seek is a museum piece—admire it, emulate it, but do not daily drive it. : Users could share their current browser tab
: A new button was added to the button bar and the "Awesome Bar" (address bar) to allow users to instantly view and sync tabs from other devices. Do not enter your passwords, credit cards, or
Resolved a bug where pages failed to load if the "Accept third-party cookies" setting was set to "Never".