// Change the billing_email to not requỉed
add_filter('woocommerce_checkout_fields', 'chuyennhanali_custom_email_required', 999999);
function chuyennhanali_custom_email_required($fields) {
    $fields['billing']['billing_email']['required'] = false;
    return $fields;
}

// checked terms and conditions by default
add_filter( 'woocommerce_terms_is_checked_default', 'chuyennhanali_wc_terms', 999999 );
function chuyennhanali_wc_terms( $terms_is_checked ) {
	return true;
}