Code-Snippets-Functions/Execute a function on a child site/WooCommerce/remove-billing-phone-validation-on-checkout.txt

add_filter( 'woocommerce_billing_fields', 'custom_billing_fields' );
function custom_billing_fields( $fields ) {
    // Only on checkout page
    if( is_checkout() && ! is_wc_endpoint_url() ) {
        $fields['billing_phone']['required'] = false;
    }
    return $fields;
}

// Remove string "(optional)" from billing phone field
add_filter( 'woocommerce_form_field' , 'remove_checkout_optional_fields_label', 10, 4 );
function remove_checkout_optional_fields_label( $field, $key, $args, $value ) {
    // Only on checkout page
    if( is_checkout() && ! is_wc_endpoint_url() && $key === 'billing_phone') {
        $optional = '&nbsp;<span class="optional">(' . esc_html__( 'optional', 'woocommerce' ) . ')</span>';
        $field = str_replace( $optional, '', $field );
    }
    return $field;
}