Use this code to Custom CSS box. Replace Pixabay with your logo image URL.

footer.sections:before {
    content: "";
    display: block;
    margin: 0 auto;
    background-image: url(https://cdn.pixabay.com/photo/2024/02/07/16/15/flower-8559381_1280.jpg);
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
    position: relative;
    top: -50px;
    width: 100px;
    height: 100px;
}
footer.sections {
    z-index: 9999999 !important;
}

Result: