pr_demo_get_price_html.php

<?php
/**
 * Filter price for non-logged-in users
 */
function pr_demo_get_price_html( $price, $product ) {
    if( !is_user_logged_in() ) {
        // Add a custom message here to display instead of the price
        return __( 'Price on application', 'your_textdomain' );
    }
    return $price;
}
add_filter( 'woocommerce_get_price_html', 'pr_demo_get_price_html', 10, 2 );