Must I use LibreOffice version 4.3.2.2 for a 2008 imac If so, how do I retrieve it from the archive?

Office 2008 came with the imac

What version of MacOS do you have?

System Requirements on Wiki

4.3.2.2 can’t be a recommended version for any OS: if your OS support is limited to, say, LibreOffice 4.3 (which is the case for macOS 10.6 & 10.7), then it’s recommended to use the latest bugfix release of the 4.3 series (which is 4.3.7.2).

Which can be downloaded from 4.3.7.2