Hello,
Try this one:
div.wpforms-container-full,
.elementor-26 .elementor-element.elementor-element-492ecde > .elementor-widget-container,
.elementor-26 .elementor-element.elementor-element-3e607aa > .elementor-widget-container
{background-color: rgba(255, 255, 255, .0)!important;
}
Regards