If you wish to invite your audiences to submit a "story" — in text form — follow the instructions in the section "Standard sweepstakes / contest app configuration," and then use the custom form to request the story text. All the stories will be moved into the Content Manager for moderation and review.
Story sweepstakes / contests are useful for asking audiences to answer questions about their 'favorite' phrase associated with your brand, or name something associated with your brand, offer recipes, solutions, or ideas, and many more similar use cases.
Managing entries and picking winners
To manage contest / sweepstakes and pick winners, see the section "Choosing sweepstakes or contest winners" in the Content Moderation forum.