Let me walk you through a method that not many people try but that works really well if you are using an Android device 
So the whole idea here is that Android is way more open about notification data than iPhone. There are apps specifically built to capture and store notifications, and one of the best free ones is called “Notification History Log” by SIVA Apps. Here is how the whole thing plays out:
You open the Play Store and search for Notification History Log. Install it. When you launch it, it will ask for notification access. Grant that. From that moment, every notification that lands on your phone gets stored in the app’s log, including message previews from Snapchat.
Now here is the best part. Even if you swipe the notification away without thinking about it, it is still saved in the log. So later that day, or even a few days later, you can open the app and scroll back through everything.
The messages show up exactly as they appeared in the notification banner. Short messages show fully. Longer ones get cut off at whatever the system character limit is for notifications, which is usually around 80 to 100 characters.
I started using this after missing an important message from a friend because I had accidentally swiped away the notification before I could read it. After that, having everything logged in one place just made life easier. You get peace of mind knowing the preview is saved even if the chat opens and disappears. It is simple, free, and requires no special permissions beyond notification access 