You are checking your test account on a device with the latest version of the Gmail App? The email with the code is sent direct to the promo tab? You can pull down to refresh what is in the bundle by pulling down on the promo tab screen (can repeat). Also, if the code has an expiration date that hasn't started or is expired, then your email cannot populate in the bundle.
Your ESP may be stripping the script tag - Sometimes there are special instructions (like add XML into body). Have you looked at your sent html to make sure the annotation is there and working? Check Show original, copy and paste into the markup tool (however if the date is an issue the markup tool will still display all but the expiration date).
The script tag can be added to the head of your email template(s), you can customize the 5 features for the campaign (can be populated with merges or dynamically - should be similar to your current creation process), and then you are all set. For the images, the goal was that you could use the same imagery from the body of your emails (brands have different ways of handling this, such as having a version of the image in the email body made at 538x138). However, all the information for the enriched preview is information already in your email. Mix and match the features to create the best enriched preview to drive your goals (if not using a feature, leave blank).
email help desk
I know this issue is ancient, but in case someone else needs a remedy... Outlook doesn't resize images, so the image needs to be exact size you want it to appear within the newsletter. In looking at the header image URL in your code, the size is 1213x191. You'd need to create a version of the image sized to the newsletter header spec (e.g. 537x85) and use that one instead.
This isn't only an issue with Selligent. It happens in other ESPs delivering messages to Outlook.