Stop the rubbing and give them space. A growl warns that this handling is too much right now. Do not scold it or pin the dog down. Check for a sore paw, skin irritation, matted coat or discomfort around an area the towel touches. If the growling is new or the dog seems painful, ask your vet before trying another grooming session.
Manage the wet dog without making them endure rough drying. Use a safe, warm area and a towel placed where they can choose to stand, keeping the floor from becoming slippery. Ask your vet or groomer what drying is necessary for this dog's coat or health. The article on dogs resisting paw wiping has related handling ideas, but a dog who has growled needs the bite risk respected.
Later, when there is no time pressure, show a dry towel and reward an easy glance. Practise a brief, voluntary touch in a comfortable area only if the dog remains relaxed. A qualified reward-based professional can help plan the steps. Never use a hair dryer or restraint as a shortcut without checking how your dog responds.
Today, separate warmth and hygiene from the need to finish a particular drying method. Your dog can be safe and dry without a fight.
Sources: Dogs Trust on choice-based handling, VCA on pain as a cause of handling changes, VCA on aggression warnings and safety.