The Keywords filter in the search sidebar (Creator Filter section) searches creator profiles for comma-separated terms. By default it matches against the creator's display name, username, bio and the hashtags they use. With the "Search in" toggles below the input you control which fields are searched: Bio (profile description), Hashtags (hashtags the creator uses) and Website (websites and external links in the profile).
Multiple plain keywords are combined with OR — a creator matching any of them can appear. Multi-word terms are matched as phrases. Prefix a term with + to make it required and with - to exclude it (see the entry on excluding keywords). Matched terms are highlighted directly in the bio and hashtag chips of the result list, so you can see why a profile matched.