All modern viewers updated since 2020 should have the capability to handle EEP sky items, such as up-to-date Firestorm, Black Dragon, or LL viewers. These are the new and awesome replacements for windlight settings that allow incredibly fine control including custom textures, new shader choices, and deeper configuration in addition to being easily shareable.
Check with your viewer provider or their in-world group for help if they are missing for you.

To view them YOURSELF:
World->Environment->My Environment
OR
Firestorm Quick Preferences->Sky

To set them on your PARCEL:
About Land->Environment

To set them on your SIM:
Region->Environment

Here are some of the ways you can easily edit them for yourself or your parcel, including the super neat “customize day cycle” which will let you set up your favorite EEP skies in an automatically playing, highly configurable list: