Hi, we don't provide any higher version for macOS 10.14.6. 115 ESR is the last one and even if you download Firefox 128 it wouldn't work. You have to upgrade your OS to 10.15 to be able to use higher version of Firefox.

My IOS is version 10.14.6

You OS is macOS as iOS is the mobile OS for iPhones just like the similar iPadOS is for newer iPads.

To run Firefox 116.0 and later including Fx 145.0.2 release and Fx 140.5.0esr requires macOS 10.15 (ten.fifteen) at minimum. https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support

If you cannot update your macOS to 10.15 or later then you can try to change your Firefox version number to fool the Chase bank site as they are looking for Firefox 128.0 and later.

1. In a new tab, type or paste about:config (with a colon) in the location (address) bar and press Enter/Return. Click the button accepting the risk.
2. In the search box in the page, type or paste forceVersion and pause while the list is filtered
3. Double-click the network.http.useragent.forceVersion preference to display an editing field, and change the value to 128 or 140 then press Enter/Return or click the blue check mark button to save the change.