"Drop It" Cue
Forcibly taking something from a dog and punishing them for growling can lead to serious Resource Aggression. You may be scary enough for them to concede, but children are often bitten. Teach your dog to happily give you what they have instead.
If your dog isn't interested in toys then you will want to find something they will play with but are not overly possessive of. Toilet paper roll cob, plastic lid, etc.
Growling over resources like toys and bones is normal behavior and not a cause of concern. If it goes beyond that then it can be a serious issue. Please schedule a private lesson with us to correct the behavior.
Emergency: If your dog has something bad that s/he is not willing to drop do an emergency trade. Run to the kitchen and find something yummy and offer it to your dog. Use the treat to move your dog away from the object and pick it up while they are eating the treat.