Tokisan Games, the creator of the popular Terrain3D plugin, offers for download and use under the MIT license the Sky3D add-on, which is written entirely in GDScript, for the open-source Godot 4.3+ game engine.
Sky3D will make it easy to implement in your game automatically rotating sun, moon and stars; Dynamic clouds and atmosphere changing according to the cycle; Combined controls for adjusting lighting and camera exposure; Game time management: current time, day length, day or night.
Details and download option are here.