This approach is a bit different than the standard flat-face lightboxes. It requires a few more prints and a bit more work on the assembly side but the results provide more depth than the more popular methods of making these. I've been building boxes like this before it became a trend. Parts are printed face down so you can take advantage of nicer surface options like the textured build plates.

Give the faceplate/lid a quicksand for good glue adhesion and then line up the diffuser with the back of the faceplate and glue in place. Use your choice of super glue for the diffuser.

After allowing some time for the glue to set up, use a blade to cut away the support branches for any of the floating bits within the text/font. Hit it with a torch to clean up any marks your blade leaves.

LED used are fully addressable WS2812B and can be found here: https://www.amazon.com/dp/B08H26BD5Z?psc=1&ref=ppx_yo2ov_dt_b_product_details

The cables are all hand-sleeved and shrink-wrapped using the following items:

Shrink Tube: https://www.amazon.com/dp/B07FPDBGYH?psc=1&ref=ppx_yo2ov_dt_b_product_details

Cable Loom/Sleeve: https://www.amazon.com/dp/B07FW86XV6?psc=1&ref=ppx_yo2ov_dt_b_product_details