Literally drag&drop into your game, can confirm they all work as shown (they even have parameters to change how they look!)
Some examples:
God rays - Godot Shaders (2D games)
[ REDACTED ] - Godot Shaders (3D games)
Dashed Grid (The Best Darn Grid Shader (Yet)) - Godot Shaders (3D games)
TRUE BoTW Toon Shader! - Godot Shaders (3D games)
and ofc you can change these realtime too (see circular pattern - Godot Shaders)