Browser to support old iPad

I have an old iPad Mini 2 running IOS 12.5.6.. I’m getting messages from web sites that they no longer work with Safari of that version of IOS. I’ve tried to install Firefox first then Google Chrome and in both cases, I again got a message that these browsers are not compatible with 12.5.6 so I couldn’t download/install them from the Apple App Store.

I realize this is quite an old iPad and I will be getting a more current iPad before year end, but is there any browser that is compatible with 12.5.6 that is easy to install and use (senior citizen with somewhat limited technical skills).