Adding Images to Checkboxes

ul#wpforms-1000-field_25 li.choice-1 label:before {

    content: "";

    display: inline-block;

    background-image: url(http://yoursite.com/wp-content/uploads/2019/10/your-image-filename.png);

    background-size: 100%;

    height: 45px;

    width: 30px;

    background-repeat: no-repeat;

    position: relative;

    right: 5px;

    top: 20px;

}