Please explain the problem in detail.

Are you creating a Firefox account? It's not mandatory to do that to use Firefox as a web browser.

An account would be valuable if you want to use certain Mozilla services. Here's an article with more information about those: Access Mozilla Services with a Firefox Account.

Does that make sense?

Thank you jscher2000 and FredMacD. I want download firebox and I have to create my account. I must set a second device : but I haven't smartphone. I have got the file .dmg, and i can open firebox, but I think the install is not finished, because I can't put the firebox icon in the dock on my iMac, and the icon is just an alias.

errata : box --> fox !

hi, as it was said you don't need an account or a mobile device to use firefox (the first tab you see when you install firefox might lead you to that but you can just close it). in order to install firefox on your system, please follow the instructions at How to download and install Firefox on Mac!

Thank you philipp, my issue is solved. I was not smart as a fox !

no worries, we're here to help. have fun with your firefox :-)