Forcing API permissions doesn’t mean that only administrators or shop managers can access them.
Authentication is not forced by user role.
How do you force API permission?
It’s actually pretty easy. All you need to do is apply a filter based on the method of the routes you want to force permission on. There are no parameters required. Just return an array of the API routes you wish to force permission on. Filter name:cocart_api_permission_check_{method}
Replace {method} with get, post, put, delete or options.