Firefox Account has been renamed as Mozilla Account since November 2023. You are using a Mozilla Account by posting thread on the support.mozilla.org community support forum. You do not need a Mozilla Account to use the Firefox web browser. This lists what you use the Mozilla Account for https://support.mozilla.org/en-US/kb/access-mozilla-services-firefox-account#w_what-services-can-i-use-with-a-mozilla-account