Uncaught TypeError: Cannot read properties of undefined (reading ‘clientX’)

Good morning! Im trying to move some figures while im moving the cursor, i dont know why this is not working since I did the same on other page and it works:

const scaleFactor = 1 / 20;


function movebackground(event) {
    const shapes = document.querySelectorAll(".shape")

    const x = event.clientX * scaleFactor;
    const y = event.clientY * scaleFactor;

    for (let i = 0; i < shapes.length; ++i) {
        const isOdd= i % 2 !== 0;
        const boolInt = isOdd ? -1: 1;

        shapes[i].style.transform = `translate(${x * boolInt}px, ${y * boolInt}px)`
    }

    console.log(shapes)
}

movebackground()

I tried another ways to solve it but still with the same issue