Giving feedback from the TestFlight app is easy. There are two-ways:
You may send as much feedback as you like - the more the better!
You can give in-app feedback by taking a screenshot of the app, and select the screenshot when it appears in the lower-left hand corner:

make a screenshot

click “Done” then
“Share Beta Feedback”

Share the feedback 🎉
In TestFlight, select the Wishtale app - do NOT tap the “OPEN” button to open the app. Tap within the green box indicated:

Then select “Send Beta Feedback” as indicated by the green box:

On the feedback screen, type your feedback in the white box and select “Submit” in the upper-right corner when you are finished. This will send the feedback immediately.
You may send as much feedback as you like - the more the better!