Your computer still supports Mozilla, and we still provide security updates for your browser. Our latest version 115.29 ESR was released October 14, 2025.

I guess your bank doesn't like this version. So you can change your Firefox version number. This might fool their site. Here's how:

1. In a new tab, type or paste about:config in the 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.

https://support.apple.com/108382

If you can update your macOS to 10.15 (ten.fifteen) or later then you will be able to run the current versions of Firefox as in Firefox 144.0.2 or Firefox 140.4.0esr.