Woocommerce Shop page variation product button replace with add to cart button

Do you mean you need to replace the button of select options with add to cart

Please check below code

add_filter( 'woocommerce_product_add_to_cart_text' , 'custom_select_options_text' );
  function custom_select_options_text() {
  global $product;
  $product_type = $product->product_type;
  switch ( $product_type ) {
  case 'subscription':
  return __( 'Options', 'woocommerce' ); /*change 'Options' for Simple Subscriptions */
  case 'variable-subscription':
  return __( 'Options', 'woocommerce' ); /*change 'Options' for Variable Subscriptions */
  case 'variable':
  return __( 'Options', 'woocommerce' ); /*change 'Options' for Variable Products */
  case 'simple':
  return __( 'Add to Cart', 'woocommerce' ); /*change 'Add to Cart' for Simple Products */
  break;
      }
  }