I'm newbie with JavaScript and I tryed to store the Vector position and whith two buttons (forward and backward) to move the Camera to that specific position. Also I tried to use 'gsap' to have soft movements but the code don't work.

//Coordinates
let positionIndex = 0;
const positions = [
    {
        x: -0.05,
        y: 0.6,
        z: -0.17
    },

    {
        x: -2,
        y: 1,
        z: 1
    },

    {
        x: 0.3,
        y: 0.6,
        z: -0.6
    }
]

//on buttonforward clicked
var element = document.querySelector(".button-1");
element.onclick = function MoveUp(){

if(positionIndex) == 3
{
    positionIndex = 0;
}
else
{
    positionIndex += 1;
}}

camera.position.x = positions[positionIndex].x
camera.position.y = positions[positionIndex].y
camera.position.z = positions[positionIndex].z


//on buttonbackwards clicked
var element = document.querySelector(".button-2");
element.onclick = function MoveDown(){

if(positionIndex) == 0
{
    positionIndex = 3;
} 
else 
{
    positionIndex -= 1;
}}
camera.position.x = positions[positionIndex].x
camera.position.y = positions[positionIndex].y
camera.position.z = positions[positionIndex].z

Someone can give me advice?

Thank you.