Hello, may I ask about the use case here as there are many things you can do instead of disable file sharing. The very fundamental of Teams is collaboration so perhaps you shouldn't use it but instead SharePoint/Groups with more restrictive permissions? But you can for ex. disable the SharePoint license so the users won't have OneDrive for business (not optimal). OneDrive is being used when sharing files in chats and group chats. If this would be done the users can still share files using standard channels which belong to the SharePoint document library.