Seven weeks? That's very young to leave his litter. But you have him and now and need to deal....
I agree about not adding tasty extras, but I've never just poured dry kibble in a bowl and expected enthusiasm, and every breeder I know softens kibble with a liquid puppy formula or at least warm water.
You can try a different brand or flavor of kibble to see if it's a matter of taste. So if the kibble you have is chicken based, try lamb, turkey, or beef. Like that.
I would not feed a raw or home cooked diet to a puppy. At that age getting the nutritional balance wrong can do real damage, and getting it right takes a lot of research.
My 10 week old came home with canin he didn’t like it either and he wouldn’t eat and he’s a beagle, so I started wetting down his food,and I bought puppy food Iams and kept him on water down food gradually drying it up, now he gets just dry @ 15 weeks (still is an outside vacuum, eats everything)
Royal Canine is a medium quality food. If your puppy doesn't like it, try something else.
When my dog was a puppy, she wouldn't touch the food I got her either. Tried a couple different brands, then once she snagged a bite of my adult dogs food, that is the only thing she would eat.
My former vet, who studied nutrition, told me that if you feed a quality food, there is no need to do a "puppy food"
It's completely ok if your dog isn't eating dry food. Try for some other one. You can feed your dog biscuits and milk. You know the good thing about dogs is they can eat almost anything. Or you can bring some canned products. They aren't dry. Don't stick your dog to a single food. Dogs are real foodies, and they can't resist eating treats. So don't panic about diet; just give him something healthy and delicious.
What was the breeder feeding the dog? I try to stick with the same food, even if I don't agree, for a few weeks during the transition to a new home. Then you can slowly (slowly!) change over to something you prefer. Puppies have a difficult enough time adjusting. I try not to add more to the mix.