Download 3D Target Cursor Marker Free Unity. 

A simple 3D target cursor

No textures needed
Color can be adjusted
Just uses an animation clip
works with LWRP/HDRP/classic pipeline (material needs to be converted) – no custom shader
Includes a sample project on how to use it with e.g. a NavMeshAgent.

Simple example code

// Cache it.

FeedbackPointer _feedbackPointer = new FeedbackPointer();

// Initialize it.