hi @cariatari
In wcff 3.0.0 goto include/wcff-builder.php line number 1176
change entire line like $html = '<select multiple data-has_field_rules="'.$has_field_rules.'" data-is_pricing_rules="'.$_is_pricing_rules.'" class="' . $_ptype . '-field ' . $_class . '" name="' . esc_attr($_meta["name"] . $_index) . '" ' . $_ptype . '-type="select" ' . $_ptype . '-pattern="mandatory" ' . $_ptype . '-mandatory="' . $_meta["required"] . '" ' . $_cloneable . ' ' . $_readonly . ' >';
We will add this option next release.
`