The Open Office extension provides a document conversion facility if Open Office or LibreOffice is already installed on the system. In order to use the Open Office extension,
LibreOffice is available directly from their website at:
www.libreoffice.org/download/download/
These are the latest releases for most deb and rpm based linux distributions and for windows and macOS.
The packages are large, and in the case of deb packages are themselves a collection of deb packages.
Note that with these newer versions of the open office extension, you cannot already have an instance of OpenOffice running when using GLI, you will need to terminate any previously running instance. It is also unlikely that you can get a separate instance of OpenOffice running after quitting GLI. If you wish to do so, you will need to use Task Manager to terminate the open office process launched by the extension upon running GLI.