Sharing a spreadsheet
A few notes before getting started: First, you can collaborate only with files stored in OneDrive, OneDrive for Business, or SharePoint Online, so make sure any files you want to share are stored there and that you’re logged into your Office 365 account.
Second, real-time collaboration works in Excel only if you have AutoSave turned on. To do it, choose the “On” option on the AutoSave slider on the top left of the screen. (This slider shows up in version 1707 Build 8326.2058 or later, but no versions before that. It’s a convenient way to tell whether you’ve got a version of Excel that allows for live collaboration).