Wow! This is one impressive site, a true treasure for anyone who makes renders regardless the software used.
One of the best resources for HDRI images in a huge quantity and quality.
And wait for it….
All HDRIs are licenced as CC0 and can be downloaded instantly, giving you complete freedom.
No paywalls, email forms or account systems.
But if you are overwhelmed by the usefullness and appreciate the content and like to support the Creator you can do so on Patreon.
Being a Patron comes also with extra advantages.
Check it out!