Bunnyhopping C++

Hello guys, I want to program a bunnyhop script with my C++ on Unreal Engine 4.

But, the vectors I have attempted to program don’t seem to work, I used the help from this website as I am still learing C++: Bunnyhopping from the Programmer's Perspective


 // accelDir: normalized direction that the player has requested to move (taking into account the movement keys and look direction)
    // prevVelocity: The current velocity of the player, before any additional calculations
    // accelerate: The server-defined player acceleration value
    // max_velocity: The server-defined maximum player velocity (this is not strictly adhered to due to strafejumping)
    private Vector3 Accelerate(Vector3 accelDir, Vector3 prevVelocity, float accelerate, float max_velocity)
        float projVel = Vector3.Dot(prevVelocity, accelDir); // Vector projection of Current velocity onto accelDir.
        float accelVel = accelerate * Time.fixedDeltaTime; // Accelerated velocity in direction of movment
        // If necessary, truncate the accelerated velocity so the vector projection does not exceed max_velocity
        if(projVel + accelVel > max_velocity)
            accelVel = max_velocity - projVel;
        return prevVelocity + accelDir * accelVel;
    private Vector3 MoveGround(Vector3 accelDir, Vector3 prevVelocity)
        // Apply Friction
        float speed = prevVelocity.magnitude;
        if (speed != 0) // To avoid divide by zero errors
            float drop = speed * friction * Time.fixedDeltaTime;
            prevVelocity *= Mathf.Max(speed - drop, 0) / speed; // Scale the velocity based on friction.
        // ground_accelerate and max_velocity_ground are server-defined movement variables
        return Accelerate(accelDir, prevVelocity, ground_accelerate, max_velocity_ground);
    private Vector3 MoveAir(Vector3 accelDir, Vector3 prevVelocity)
        // air_accelerate and max_velocity_air are server-defined movement variables
        return Accelerate(accelDir, prevVelocity, air_accelerate, max_velocity_air);

So if possible, please help me. I want to add speed on every jump, just like the Source Engine bunny hopping. I also want AutoJump if possible.