Since you can use food at the fence posts (instead of bumpers/dummies), YES - you can take this course with a dog which lacks retrieving drive or enthusiasm.
The course covers this option and really encourages the use of food occasionally for most dogs, to keep enthusiasm high.
However, to avoid your dog believing that there are never bumpers/dummies at the posts, ideally your dog will retrieve at least once per session should they find no food at the post and a bumper/dummy instead.
If your dog is unable to retrieve even one bumper/dummy, you probably have a retrieving problem which would be addressed on the
Clicker Retrieve course.