Buc-ees LED Lightbox.
I used aluminum reflective tape on the inside of the box and also on the backplate. Here is a link to the LED's that I used.
https://www.amazon.com/dp/B09SHKLNTQ?ref=ppx_yo2ov_dt_b_product_details&th=1
I went around the inside of the box twice with the LED's and kept as far to the back as I could to diffuse more of the light.
The print file is for a 5 color print but I currently only have one AMS so I had to change the yellow background to white on my example print. I hope to get another AMS soon.