WooCommerce Every product add custom email and phone number. If no one is provide will display default one on Single Product Page underneath Title

add_phone_email_to_single_product.php

<?php
// Preview Backend: https://i.imgur.com/hyLOnlI.png
// Preview Frontend: https://i.imgur.com/hyLOnlI.png

// Add new tab in the backend.
add_filter( 'woocommerce_product_data_tabs', 'sfc_add_product_data_to_tab' );
function sfc_add_product_data_to_tab( $default_tabs ) {
	global $post;
	$tabs = array(
		'sfc_phone_email' => array(
			'label' => __( 'Phone & Email', 'storefront' ),
			'target' => 'sfc_phone_email',
			'class' => 'sfc_phone_email',
			'priority' => 10,			
		)
	);
	return array_merge( $default_tabs, $tabs );
}

// Add new tab content in the backend.
add_action( 'woocommerce_product_data_panels', 'sfc_data_panels' );
function sfc_data_panels(){
	global $woocommerce, $post;
	$sfc_phone_number = get_post_meta( $post->ID, '_sfc_phone_number', true );
	$sfc_phone_email  = get_post_meta( $post->ID, '_sfc_phone_email', true );
	$sfc_phone_number = isset( $sfc_phone_number ) ? sanitize_text_field( $sfc_phone_number ) : '';
	$sfc_phone_email  = isset( $sfc_phone_email ) ? sanitize_email( $sfc_phone_email ) : '';
	?>
	<div id="sfc_phone_email" class="panel woocommerce_options_panel">
		<div class="options_group pricing show_if_simple show_if_external">
			<p class="form-field">
				<label for="sfc_phone_number">Phone Number: </label>
				<input type="text" class="short wc_input_phone" name="sfc_phone_number" id="sfc_phone_number" value="<?php echo esc_attr( $sfc_phone_number ); ?>" />
			</p>
			<p class="form-field">
				<label for="sfc_phone_email">Email: </label>
				<input type="text" class="short wc_input_email" name="sfc_phone_email" id="sfc_phone_email" value="<?php echo esc_attr( $sfc_phone_email ); ?>" />
			</p>
		</div>
	</div>
	<?php
}

// Save content in the backend.
add_action( 'save_post', 'sfc_save_product_data', 10, 3 );
function sfc_save_product_data( $post_id, $post, $update ) {
	if ( isset( $_POST['sfc_phone_number'] ) ) {
		update_post_meta( $post_id, '_sfc_phone_number', sanitize_text_field( $_POST['sfc_phone_number'] ) );
	}
	if ( isset( $_POST['sfc_phone_email'] ) ) {
		update_post_meta( $post_id, '_sfc_phone_email', sanitize_email( $_POST['sfc_phone_email'] ) );
	}
}

// Display content in the backend.
add_action( 'woocommerce_before_add_to_cart_form', 'sfc_display_phone_email_after_product_title' );
function sfc_display_phone_email_after_product_title() {
	global $post;

	$sfc_phone_number = get_post_meta( $post->ID, '_sfc_phone_number', true );
	$sfc_phone_email  = get_post_meta( $post->ID, '_sfc_phone_email', true );

	// Sanitize and set default values.
	$sfc_phone_number = ( ! empty( $sfc_phone_number ) ) ? sanitize_text_field( $sfc_phone_number ) : '01600000000';
	$sfc_phone_email  = ( ! empty( $sfc_phone_email ) ) ? sanitize_email( $sfc_phone_email ) : '[email protected]';

	// Display phone number if set.
	printf('<div class="sfc_phone_email"><div><a class="sfc_phone_number" href="tel:%s"><i class="fa fa-phone mr-4"></i>%s</a></div>', esc_attr( $sfc_phone_number ), esc_html( $sfc_phone_number ) );
	printf('<div><a class="sfc_phone_email" href="mailto:%s"><i class="fa fa-envelope mr-4"></i>%s</a></div></div>', esc_attr( $sfc_phone_email ), esc_html( $sfc_phone_email ) );
}

style.css

.sfc_phone_email i {
    margin-right: 10px;
}

.sfc_phone_email a {
    color: #111;
    text-decoration: none;
    margin-bottom: 6px;
    display: inline-block;
    transition: all 0.3s ease;
    font-size: 16px;
    font-weight: 600;
}

.sfc_phone_email a:hover {
    color: #f00;
}

[Preview Backend]

[Preview Frontend]