If you subscribe to Microsoft 365, then SharePoint Online is part of your subscription.  SharePoint Online is the ideal approach for auto-saving files to a shared file location.  SharePoint Online has a robust feature set, numerous integrations, and is the foundation of Microsoft Teams.  In addition, users can co-author documents, meaning multiple users can be updating a single document at the same time.

Steps for setting up SharePoint as your File-Save location:

1. Set up your site in SharePoint (see SharePoint Site collection Setup)
2. Add the SharePoint URL to the File Auto-Saving section (in Admin >> Account Settings) of the Dashboard (see File Auto-Saving in Dashboard Account Settings)
3. Register each of your users
   • In the Excel or Word tool, have users go to Add-Ins >> Help >> Support Functions >> Update license via web to download your company's SharePoint settings to their desktop
   • Next, have users go to Add-ins >> Settings >> SharePoint Settings >> Register as SharePoint user using their Microsoft 365 login information
   • Next, users should test their SharePoint permissions by going to Add-ins >> Settings >> SharePoint Settings >> Check SharePoint permissions

 
More Information:

• Setting up a SharePoint Online Site Collection
• File-Auto Saving Settings in Dashboard
• Account Settings in Dashboard