If you want to restore trust after spanking a cat, you need to spend more time with the cat, stroke the cat's head, cheeks and back appropriately, and feed the cat some of its favorite snacks, such as canned food, freeze-dried food, cat strips, etc. Over time, the cat will forget that you spanked it and will trust you again.
Tips:
It is best not to spank cats, because cats are very sensitive and prone to stress reactions, so it is best to Be patient and teach your cat.