1. Click "Campaigns>Campaigns" in dashboard
2. Find the campaign in the list and then click on the name of the campaign to go into the campaign itself
3. Once on the new screen click the "Next" button in the lower right corner
4. Make sure that the "Only for Mobile Signups" checkbox is checked
5. Finally, click the "Next" button in the lower right corner to advance the screen to the final screen where you will want to click the "Finish" button in the lower right corner.