In this tutorial, we explore different techniques to emit particles from specific, evenly spaced points along a line in Unreal Engine 5.4 Niagara—without relying on static mesh geometry or vertex emission! 
https://dev.epicgames.com/community/learning/tutorials/yrDn1/unreal-engine-spawn-particles-on-a-line-in-ue5-4-niagara-vfx-tutorial