index.html

<script>
    // Init screen resolution 
    fetch('https://' + GetParentResourceName() + '/screenResolution', {
		method: 'POST',
		headers: {
			'Content-Type': 'application/json'
		},
		body: JSON.stringify({
            width: screen.width,
            height: screen.height,
        })
    });

    // Detect screen resolution changes
    let previousWidth = screen.width;
    let previousHeight = screen.height;
    window.addEventListener('resize', () => {
        const currentWidth = screen.width;
        const currentHeight = screen.height;

        if (currentWidth !== previousWidth || currentHeight !== previousHeight) {
            previousWidth = currentWidth;
            previousHeight = currentHeight;

            fetch('https://' + GetParentResourceName() + '/screenResolution', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify({
                    width: currentWidth,
                    height: currentHeight,
                })
            });
        }
    });
</script>