Projectile motion arc 2d

I am making a tower defense game and have a code that makes my projectile go straight to the moving destination.
I want to reproduce the same circular motion of the projectile toward in motion destination in the wizard’s tower as in the video below.
Any idea?

My code:

transform.position = Vector2.MoveTowards (transform.position, target.transform.position, Time.deltaTime * Speed);
Vector3 dir = target.transform.position - transform.position;
float angle = Mathf.Atan2 (dir.y, dir.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.AngleAxis (angle, Vector3.forward);

Including the answer here for someone who in future needs the same thing as me.
After some research and testing I got the desired effect based on the blog below: