If goat milk powder is unavailable, consider the following alternatives to feed kittens:
Milk: While not the best choice, milk can be used as a temporary substitute. However, kittens may be lactose intolerant to milk, so it is recommended to feed them only small amounts and observe for any adverse reactions.

Pet soy milk powder: This is a milk powder specially designed for pets and can be used as an alternative to goat milk powder. Compared to cow's milk, pet soy milk powder is easier for kittens to digest.
Infant formula: Some infant formulas are specifically designed for babies with cow's milk allergies, so it may be more suitable for a kitten. However, please consult a veterinarian before using it.