First, make sure you have the permission to do so. Then, look for a 'share' or 'repost' button. If there isn't one, you might need to manually select and copy the text and paste it into your story. Just be careful to credit the original source.
Well, it depends on the platform you're using. Some platforms have a straightforward 'repost' feature. If not, you might have to copy the text and then paste it in your story while giving proper attribution to the original author.