If you work with Office 365 and all employees have their own work accounts, you can choose this service to view and edit documents in your portal.
To edit a document, you must first log in with your Office365 work accoun(email@example.com). To do this, open the document for editing or from the viewer, click Edit in Office365.
If you have a personal account with Office 365 for Home subscription and you want to edit documents in the cloud, select Edit in MS Office Online option.
Then click Edit Document > Edit in Browser.
Edit document using MS Office Online.
Don't forget to save file in Bitrix24 window.