Most likely is that your instagram connections has fallen off. It's nothing you have done, it just happens sometimes! You should see a warning banner and a blue button to take you to the correct place to connect it. If not, ensure you're on your timeline :<https://hq.ampjar.com/emails/dash/overview> and click on Create New Campaign in the top right corner of the page or click Create campaign now in your timeline list.
If you have a campaign that says Not Sent then you can click to rescue that campaign and we'll ask you to tell us when you'd like to send your next campaign.