Rigidbody not able to be linked to object within unity for some reason?

I am attempting to link my rigid body here, but for some reason it will not show up. I plan to change the velocity of an object when it reaches a specific speed on the x & y axes. I am attaching relevant code below along with a picture of the area:

/* THIS IS TO CORRECT THE Y AXIS BUG */

public Rigidbody rb;

private bool ballIsStuck = false;

/* Variables over */

void Start()
{
    paddleToTheBall = transform.position - paddle1.transform.position;
    myAudioSource = GetComponent<AudioSource>();

    // rigidbody to rb

    rb = GetComponent<Rigidbody>();
}

// Update is called once per frame
void Update()
{ // ball lock & stick 
    if (!hasStarted)
    {
        LockBallToPaddle();
        LaunchOnClick();
    }
}

public void FixedUpdate()
{
    // Ball velocity adjustment to prevent loop

    if (rb.velocity.x > -0.1 && rb.velocity.x < 0.1)
    {
        rb.velocity = new Vector3(0.5f, 0.5f, 0f);
        ballIsStuck = true;
    }

        if (rb.velocity.y > -0.1 && rb.velocity.x < 0.1)
        {
            rb.velocity = new Vector3(0.5f, 0.5f, 0f);
            ballIsStuck = true;
        }
}

I found the problem, I needed to recognize it as a 2D instead of a regular rigidbody component.