Add caption underneath poster image block

Site URL: https://www.after-art.co.uk/

Hello

I would like to add a copyright caption underneath the poster image blocks on our site's homepage. Could you help with what CSS code I might need to add please

Thank you in advance

Jane

Add to Home > Design > Custom CSS

.design-layout-poster:after {
    content: "Photo by Tuan";
    display: block;
    text-align: right;
    color: white;
    font-size: 20px;
    margin-top: 10px;
}

Thank you - much appreciated!