After seeing a 6min TeachingTech video on YouTube I found his X test file was for only for his Patrons (crappy move IMO) but none the less, I made one for you all to use. It works VERY WELL!!!
I've used it on my Ender3 Pro and my Anycubic Mega X... Both with Cura4.8 slicer. Just increase / decrease the size in Cura to fit your bed... Works like a charm.

This object was made in Tinkercad. Edit it online https://www.tinkercad.com/things/d4woCxOm9TS