Hi,
Via the Translation tool, I got following content:
You just want to block OneDrive external sharing, but do not block SharePoint, am I right? Any misunderstanding, please let me know.
I suggest you go to go to Sharing in the SharePoint admin center, and sign in with an account that has admin permissions for your organization.
Under External sharing, specify "Only people in your organization" for OneDrive.
For more, please refer to: Change the organization-level external sharing setting.
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