Summary

I designed this so I could mount the TV very close to the wall and easily lift it off - sorta french cleat style. It can be rotated to be level. Now I can move it from wall to wall.

Almost all smaller TVs (<40") use M4 screws to attach in a 100mm x 100mm bolt pattern.
Pick up a pack of m4s at different sizes on Amazon.
This is the one I used:
https://www.amazon.com/dp/B0FQNV11TB

Make sure to hit a stud or use anchors on the Wall piece.

It took 2.5 hours to print in 2.0mm strength on my Bambu P1P.