Use shape to reveal background (or fixed layer only visible through shape)

Hello! I’ve consecutively failed in trying to achieve this effect without the need of custom code, which I think should be possible but maybe I’m just that stubborn. What I want is a big circle to follow my mouse cursor (easily achieved) and this circle to be a sort of a clipping mask, revealing a image that would just be a solid color when the circle is not on top of it.

A similar effect can be found at the cover page of Studio Thomas’s website (https://studiothomas.co.uk).

I would be very happy with any reply on how I could achieve this effect, thanks a bunch!

(I’m also available to clear out any misunderstandings that may arise due to the poor phrasing on this request)

Here is my public share link: LINK
(how to access public share link)