This is a paid asset, but now you can download 3D Target Cursor Marker Free.
Detail this asset from Unity Store: Original Link
3D Target Cursor Marker v1.0
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.
_feedbackPointer.PreparePointer(_moveToIndicator, _feedbackPointerScale);
// Use it with a 3D position.
_feedbackPointer.ShowPointer(navHit.position)
Tested in 2018.x to 2021.x but should also work in older Unity versions.
Just an animated prefab with a single material and a script placing the prefab on the NavMesh.