Change the external sharing setting for a user's OneDrive
After you set the organization-wide sharing settings for SharePoint and OneDrive, you can further restrict the external sharing for a specific OneDrive user.
Instead of changing the external sharing setting for an individual user's OneDrive, you might want to block external sharing of sensitive information for all users. To learn how, see Overview of data loss prevention policies.
Sign in to https://admin.microsoft.com as a global or SharePoint admin. (If you see a message that you don't have permission to access the page, you don't have Office 365 administrator permissions in your organization.)
In the left pane, select Users > Active users.
Select the user.
Select the OneDrive tab, and under Sharing, select Manage sharing.
Select a new external sharing level, and then select Save.
You can also change the external sharing setting for a specific OneDrive user by using Microsoft PowerShell and running the cmdlet Set-SPOSite with the parameter -SharingCapability. For more info, see Set-SPOSite.