We're always available for questions and assistance, but here's the answer ahead of time, if it helps.
The only way a dog can “ask” if they are allowed to chew on something is to go ahead and chew on it and see what you'll do. If you catch the dog in the act of chewing on something they are not supposed to, just mildly correct them, take the object out of their mouth, and give them an appropriate dog toy or bone to chew on. Then praise them for chewing on that toy/bone. If you know there are objects your dog is likely to chew on (socks, for instance), best practice is to not give the dog an opportunity to chew on those items.