odm to docx conversion is typically searched by users that own documents in a very specific OpenDocument format (global) and either struggle to open it or just look for a way to export it to one of the common formats.
Your best option to wotk with .odm file is to download one of the OpenDocument based productivity suites, for example OpenOffice or LibreOffice, open the .odm file using the Writer tool and re-save it any format you need.
Updated: October 16, 2023