Address field – make State field optional

add_filter( 'wpforms_field_properties', 'custom_address_state_optional', 10, 3 );

function custom_address_state_optional( $properties, $field, $form_data ) {

    // Check if the field is an Address field.

    if ( 'address' === $field['type'] ) {

        // Set the 'required' property of the 'state' subfield to false.

        $properties['inputs']['state']['required'] = false;

        // Remove the 'required' attribute from the 'state' subfield.

        if ( isset( $properties['inputs']['state']['attr']['required'] ) ) {

            unset( $properties['inputs']['state']['attr']['required'] );

        }

        // Remove the 'aria-required' attribute from the 'state' subfield.

        if ( isset( $properties['inputs']['state']['attr']['aria-required'] ) ) {

            unset( $properties['inputs']['state']['attr']['aria-required'] );

        }

        // Remove the 'wpforms-field-required' class from the 'state' subfield.

        if ( isset( $properties['inputs']['state']['class'] ) ) {

            $properties['inputs']['state']['class'] = str_replace( ' wpforms-field-required', '', $properties['inputs']['state']['class'] );

            $properties['inputs']['state']['class'] = str_replace( 'wpforms-field-required', '', $properties['inputs']['state']['class'] );

        }

        // Remove the 'wpforms-required-label' class from the 'state' subfield label.

        if ( isset( $properties['inputs']['state']['label']['class'] ) ) {

            $properties['inputs']['state']['label']['class'] = str_replace( ' wpforms-required-label', '', $properties['inputs']['state']['label']['class'] );

            $properties['inputs']['state']['label']['class'] = str_replace( 'wpforms-required-label', '', $properties['inputs']['state']['label']['class'] );

        }

    }

    return $properties;

}