On your template, there are designated recommended days to promote during the arc of your campaign (roughly once a week). Those have a gray PROMOTE button on the bottom of those Facebook posts in your dashboard view. You can click on PROMOTE once you've edited your content, and a window will pop up asking you to put in your budget. Simply enter it, and leave the rest to Storyblaster.
You can also promote any Facebook posts at any other time by clicking the rocket icon on the post in your dashboard view, which will also bring up the same window to enter your budget.
If you’ve selected a post that says PROMOTE on it, click on the editing pencil and you will see guidance to create the best kind of post for promotion. Follow it—it works. You will also be guided to edit a second post for that same day as we do a rotation of two posts with your one paid promotion. This makes sure targeted audiences won't always see the same ad, and we can also see what's working best and tweak along the way since we spread out a promotion over several days.
If you've clicked the rocket icon and selected any other post to promote, keep in the mind the content guidance for that day won't necessarily be the optimal content for promotion. See here for content recommendations.