Trying to download an old developer version, but main site redirects to latest version only.
I am using macOS 10.14 which is the latest that supports 32 bit binaries… and thus cannot upgrade beyond.
As a remark. I see no functional difference in between macOS 10.14 and 10.15 except for dropping 32 bit support. Hence I do not see the reason why 10.14 support was dropped from Firefox side.