See https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

''<p>deirdre.peck [[#question-1424491|said]]</p>'' <blockquote>My Macbook Air is running iOS 10.12.6, so how am I meant to update Firefox, as the TSB bank says I must to use their online software? Firefox is apparently no longer supported below iOS 10.14. I can't upgrade my iOS. </blockquote> https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support Firefox releases for Mac since 116.0 requires '''macOS''' 10.'''15''' (ten.fifteen) at minimum to run. The most current you can run on '''macOS 10.12.6''' is Firefox 115 ESR. The good news is the last update will be 115.15.0 ESR in Sept 2024 so you have another year of support. Btw '''iOS''' is the mobile OS for iPhone's and more current iPad's uses iPadOS as old ones used iOS. The iMac and Macbooks uses '''macOS''' as the operation system. To download the current Firefox 115.2.1esr see https://www.mozilla.org/firefox/all/#product-desktop-esr as make sure the '''Which version would you like?''' drop menu has 115.12.1esr selected as the old 102 .15.1esr is selected by default, though it will be the last for the old Fx 102 ESR. edit: though it appears you already have the current Fx 115.2.1esr as per your system details on right of post.