If your In-app campaign was working properly while testing but after the campaign creation, it is showing zero impressions on the dashboard, it can occur due to one of the following reasons:

• None of the customers are fulfilling your segmentation or targeting criteria.
• Users whom you have targeted, might not have opened the app. In-app campaigns are shown only when the user opens the app after you create the campaign.
• Time difference between campaign creation and expiry time is too less and none of the users have opened your app during that interval.
• showInApp() is not called on the screen on which the campaign needs to be shown.
• There are multiple campaigns created with the same trigger and segment filters but the priorities are different, so the campaign with the higher priority would be delivered to the user.
• The campaign might not show up because of the global delay condition. 
• While targeting an In-app campaign to be shown on a particular screen, you have not selected the right screen name.
• In-app module is not integrated with the SDK
• In case of a similar priority, campaigns with the latest updated timestamp would be delivered first to the user.