In this Unreal Engine 5.3 Niagara tutorial, we break down how Sprite UV Mode works and how to use it to randomize and flip your particle textures on the X and Y axes for more natural visual effects! 
https://dev.epicgames.com/community/learning/tutorials/LevMo/unreal-engine-ue5-3-niagara-basic-sprite-uv-mode-21