It looks overall to dark for a scene under daytime sky.
So the lighting from the sky is missing.
But the problem is: Sky can't be modeled with a point light. Point light still works for sun, but not for the entire sky.
So you'd need an area light for the sky, ideally with the shape of a dome. Image based lighting methods are an example, e.g. the environment map used in simple PBR demos.
The problem with area lights is that we no longer can calculate shadows using shadow maps. Shadow maps are based on rasterization, and rasterization requires a pinhole camera, or a point light.
Thus, the visibility term is often ignored, and the area light illuminates everything, even the inside of a room which has no window to see the sky.

So we really have a big problem here. Traditionally the solution was to bake global illumination offline, storing it in lightmaps, or various probe based solutions. That's limited to static scenes. If we open a door of our dark room to the outside, the now visible skylight (directly or indirectly via bounces), still does not illuminate our room. It remains dark. Supporting dynamic time of day also isn't easily possible.

Recently, realtime GI solutions become practical. E.g. Voxel Cone Tracing, RTX GI, UE5 Lumen. All based on some form of ray tracing. Ray tracing is not limited to a single common origin for all rays, so no more limitation to pinhole camera and point lights. We can trace from anywhere in any direction to get some approximation on how light bounces around in the scene.

Though, if you're fine with a mostly static scene, offline baking is still a very valid option. So i'd look on related options of your Engine on this first.