.toplevel_page_kdt_backup_plugin>.wp-menu-image::before{
    background-image: url(../img/backup.png) !important;
    background-repeat: no-repeat;
    content: "" !important;
    background-size: 26px;
    width: 28px;
    background-size: 26px;
    background-position: 1px 1px;
}