title: How to display an error message when the quantity for a product is more than 3 in woocommerce?
body: <p>I have a product added through woocommerce for my client's website.</p>
  
  <p>Now, I want to show "ADD TO CART" only if the product's qty is 3 or below. If the Qty is more than 3, then the "ADD TO CART" button should be disabled and another button called "CONTACT" should be enabled.(Or, it is fine if it displays some error message if the user choose more than 3 quantities).</p>
  
  <p>Simply says, For Quantities 3 or below - we can add to cart<br>
  For Quantities more than 3 - display error msg (or) CONTACT button </p>