https://linguaholic.com/linguablog/do-what-thou-wilt-meaning/
"The use of “do what thou wilt” in Thelema
The first use of “do what thou wilt” is from Thelema, an occult religion created by Aleister Crowley in 1904.
This phrase is one of Thelema’s central rules.
We’re not in the habit of exploring religious precepts here at Linguaholic, but in this case we need to make a quick tour through Thelema’s most important text.
In the Book of the Law, Crowley writes that “Do what thou wilt shall be the extent of the Law.”" More at link.
But what does that actually mean?
Core to understanding this is the definition of “Will” in Thelema.
To Crowley, “will” doesn’t just mean “desire” or “what you want.” Thelema is all about the spiritual improvement of all humanity, one person at a time.
That means you should interpret this phrase as a calling to find your true purpose in life and pursue it without getting distracted.
In Thelema, then, “do what thou wilt” means something like “Figure out your true spiritual purpose and then try your best to achieve it.”
They also have the Wiccan saying at the link.
Sorry. Not buying it!
I am not buying it either.¾