Change the "Add to Cart" text on the single product page based on the product ID

functions.php

/**
 * Change the "Add to Cart" text on the single product page based on the product ID
 *
 * @param string $text
 * @param object $product
 * @return string
 */
function wc_custom_single_addtocart_text( $text, $product ) {
    $products = array( 1, 2, 3 );

    if ( in_array( $product->id, $products) ) {
        $text = 'Special text';
    }

    return $text;
}
add_filter( 'woocommerce_product_single_add_to_cart_text', 'wc_custom_single_addtocart_text', 10, 2 );