Hide "Add to cart" button when the product price is zero

This may be a suitable solution according to the documentation

woocommerce_is_purchasable – filter Function name: WC_Product::is_purchasable is_purchasable() — Returns false if the product cannot be bought. https://woocommerce.wp-a2z.org/oik_api/wc_productis_purchasable/

function remove_add_to_cart_on_0 ( $is_purchasable, $product ){
    if( $product->get_price() == 0 ) {
        return false; }
    else {
        return $is_purchasable; }
}
add_filter( 'woocommerce_is_purchasable', 'remove_add_to_cart_on_0', 10, 2 );