The Microsoft 365 plugin opens office documents held in FileRun with Microsoft 365 for the web,
so they can be previewed, created and edited in the browser.
Unlike Collabora Online and ONLYOFFICE Docs, there is no server for you to install: the editor is Microsoft's own online service. In exchange, Microsoft has to be able to reach your FileRun installation, and you have to be enrolled with Microsoft before it will do so. Zoho Editor and Google Docs Editor are the other two online services FileRun can edit with.
Microsoft only opens documents from storage providers it has accepted into the Cloud Storage Partner Program. Enrolment is between you and Microsoft; FileRun cannot arrange it for you.
Your FileRun installation also has to be reachable from the Internet over https:// with a valid
certificate, because Microsoft's servers fetch the document from it.
Open the control panel, go to Files → Plugins, select Microsoft 365 and click Edit.
There is one setting:
Enable production environment — when it is off, the plugin uses Microsoft's testing
environment, which is what the enrolment process uses while your installation is being
validated. Turn it on once Microsoft has moved you to production.To make Microsoft 365 the editor that opens when a user double-clicks an office document, set it
as the default under Files → Plugins → Defaults. Otherwise it is offered in the
Open with.. menu.
If you only need to view Microsoft Office documents and not edit them, the
Microsoft Office Web Viewer plugin needs no enrolment — it only requires your FileRun
installation to be reachable online. File preview options lists it, along with the
other ways of previewing documents.