I went into my Grid, and I created a new topic. I called it "I will miss you". I didn't worry about adding images to the topic. However, I did set-up the topic so it was hidden from my students, and I provided myself with 10 minutes for the video recording. (That is the maximum amount of time you can record in FlipGrid). I recorded a response (one per student). I recorded a personalized end of year message for each student. Then I used the student's name for the display name. If you use the student's name as the display name then it will print on the QR Code. I selected print QR Codes. In the advanced setting, I set it up so nine QR Codes would print per slide. Here is a video showing you how I created my codes:
https://drive.google.com/file/d/1Iu-rBuUqlJzZWQO7pJgFTECCU4g1vZt-/view