Retrieving a clicked on notification on iPhone 8 I received a notification from Dooordash that was a coupon for 50% off my next order by a certain date with a code in the notification. Seeing this made me decide I would use it so I clicked on the notification to open doordash, placed my order, and went to add the code.  I hadn’t memorized the code fully so I went to go back to the Look at the notification but it had disappeared when I clicked on it and now I can find no way to pull it up again to retrieve the coupon code. This meant I could not get my discount from doordash and their support help said I need a screenshot of the code to get help retrieving the code which is beyond stupid as having a screenshot of the code would mean I still had it and would need no help. 

Is there anyway to pull-up recent notifications that you have clicked on? I saw nothing like that in the notification settings pages.
There's no "archive" or "history" of notifications built-in to iOS unfortunately. Each app has to individually provide such a feature.

The best hope is if you happen to have another device running the same app, such as an iPad - perhaps that device still shows the notification on its lock screen.