To mount the electronics to the enclosure we'll be using... popsicle sticks! Yes you heard me right! You can find them at your local dollar store.
These sticks work well with the built in mounting holes in the enclosure. They are inexpensive and plentiful. If you mess up it's ok just grab another! Sometimes called "craft sticks", these are actually a bit thicker than popsicle sticks and should measure 5/8" by 5 & 1/2"
When struggling deeply in figuring out how to securely mount the electronics for this project, I went to the Adafruit Discord and posted about my problem in the #projecthelp channel. The popsicle stick suggestion was given to me by user "madboger" in a matter of MINUTES after posting, and turned out to be a life saver! More info on the Adafruit Discord.