Need help to add jumping

How would I go about adding jumping to this script?
(Note, the script is for Third person movement)

    public CharacterController controller;
    public float speed = 6f;
    public float turnSmoothTime = 0.1f;
    public float gravity = 9.8f;
    //public bool isGrounded;
    float turnSmoothVelocity;
    public Transform cam;

    // Update is called once per frame
    void Update()
    {
        float horizontal = Input.GetAxisRaw("Horizontal");
        float vertical = Input.GetAxisRaw("Vertical");
        Vector3 direction = new Vector3(horizontal, 0f, vertical).normalized;
        //Debug.Log(controller.isGrounded);
        if (!controller.isGrounded)
        {
           //isGrounded = false;
            direction.y -= gravity * Time.deltaTime * 60;
            controller.Move(direction * Time.deltaTime);
            if (GetComponent<Transform>().position.y < -20f)
            {
                transform.position = new Vector3(5f, 5f, 5f);
            }
        }
        if (direction.magnitude >= 0.1f && controller.isGrounded)
        {
            //isGrounded = true;
            float targetAngle = Mathf.Atan2(direction.x, direction.z) * Mathf.Rad2Deg + cam.eulerAngles.y;
            float angle = Mathf.SmoothDampAngle(transform.eulerAngles.y, targetAngle, ref turnSmoothVelocity, turnSmoothTime);
            transform.rotation = Quaternion.Euler(0f, angle, 0f);
            Vector3 moveDir = Quaternion.Euler(1f, targetAngle, 0f) * Vector3.forward;
            controller.Move(moveDir.normalized * speed * Time.deltaTime);
        }
    }

Try some tutorials or study other code to see how they do it, then bring the knowledge to your code and integrated, same with pretty much any feature.

If you have gotten this far with the above code, it is possible that you may have neglected to understand what the code does. Until you remedy this, adding more features will be extremely difficult.

Tutorials and example code are great, but keep this in mind to maximize your success and minimize your frustration:

How to do tutorials properly, two (2) simple steps to success:

Step 1. Follow the tutorial and do every single step of the tutorial 100% precisely the way it is shown. Even the slightest deviation (even a single character!) generally ends in disaster. That’s how software engineering works. Every step must be taken, every single letter must be spelled, capitalized, punctuated and spaced (or not spaced) properly, literally NOTHING can be omitted or skipped.

Fortunately this is the easiest part to get right: Be a robot. Don’t make any mistakes.
BE PERFECT IN EVERYTHING YOU DO HERE!!

If you get any errors, learn how to read the error code and fix your error. Google is your friend here. Do NOT continue until you fix your error. Your error will probably be somewhere near the parenthesis numbers (line and character position) in the file. It is almost CERTAINLY your typo causing the error, so look again and fix it.

Step 2. Go back and work through every part of the tutorial again, and this time explain it to your doggie. See how I am doing that in my avatar picture? If you have no dog, explain it to your house plant. If you are unable to explain any part of it, STOP. DO NOT PROCEED. Now go learn how that part works. Read the documentation on the functions involved. Go back to the tutorial and try to figure out WHY they did that. This is the part that takes a LOT of time when you are new. It might take days or weeks to work through a single 5-minute tutorial. Stick with it. You will learn.

Step 2 is the part everybody seems to miss. Without Step 2 you are simply a code-typing monkey and outside of the specific tutorial you did, you will be completely lost. If you want to learn, you MUST do Step 2.

Of course, all this presupposes no errors in the tutorial. For certain tutorial makers (like Unity, Brackeys, Imphenzia, Sebastian Lague) this is usually the case. For some other less-well-known content creators, this is less true. Read the comments on the video: did anyone have issues like you did? If there’s an error, you will NEVER be the first guy to find it.

Beyond that, Step 3, 4, 5 and 6 become easy because you already understand!

If you just want a CC script, here’s one:

https://discussions.unity.com/t/855344

That one has run, walk, jump, slide, crouch… it’s crazy-nutty!!

Thank you
I did follow a tutorial for it, and i did attempt to add jumping my self, but it was too buggy regardless of what i added