Here's why:
* Adverbs modify verbs, adjectives, or other adverbs. They tell us *how*, *when*, *where*, *to what extent*, or *why* something happens.
* "Creatively" describes how something is done. For example: "She solved the problem creatively." In this sentence, "creatively" modifies the verb "solved" and tells us *how* she solved the problem.
Let me know if you'd like more examples!