Angle required to hit a coordinate (x, y, z)

I am trying to implement the mechanism shown in the below video

The player can set the velocity of the ball and where it will land on the pitch(Watch the video for 10 s). I am trying to find the angle(rotation along the X axis) at which the ball has to be thrown to reach the selected point.

The same question has been asked here
https://stackoverflow.com/questions...projection-in-3d-for-an-object-to-step-at-giv
But using the method suggested there
(based on "Angle required to hit coordinate" https://en.wikipedia.org/wiki/Projectile_motion)
I am not getting correct results.

The code that I have currently have is given below.

Code (CSharp):

1.  
2. private void LaunchBall()
3. {
4.     float angle = CalculateLaunchAngle(source, destination, velocity);
5.     rb.velocity = Quaternion.Euler(angle, 0f, 0f) * direction * velocity;
6. }
7.  
8. private float CalculateLaunchAngle(Vector3 source, Vector3 destination, float velocity)
9.     {
10.         float y = Mathf.Abs(destination.y - source.y);
11.         float xx = destination.x - source.x;
12.         float zz = destination.z - source.z;
13.         float xz = Mathf.Sqrt(xx * xx + zz * zz);
14.         float g = Physics.gravity.y;
15.         float v = velocity;
16.  
17.         float sqrt = Mathf.Sqrt((v * v * v * v) - g * ((g * xz * xz) + (2 * y * v * v)));
18.         if (float.IsNaN(sqrt))
19.             return 0f;
20.  
21.         float angle1 = Mathf.Rad2Deg * Mathf.Atan(((v * v) + sqrt) / (g * xz));
22.         float angle2 = Mathf.Rad2Deg * Mathf.Atan(((v * v) - sqrt) / (g * xz));
23.  
24.         Debug.Log("Angle 1 = " + angle1);
25.         Debug.Log("Angle 2 = " + angle2);
26.  
27.         return angle1;
28.     }
29.  

Please suggest a way forward.