title: Add a select field that will change price in Woocommerce simple products
body: <p>I need to add a select with a custom price in the single product as seen in the screenshots below;</p>
  
  <p><img src="https://i.stack.imgur.com/mE6m3.png" alt="HTML select dropdown"></p>
  
  <p><a href="https://i.stack.imgur.com/zBFkm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zBFkm.png" alt="enter image description here"></a></p>
  
  <p>The idea is that by selecting an option from (select) you can increase it to the base price.</p>
  
  <p>Without using the variations, since my idea is to do other things more, but I need help on how to do this.</p>
  
  <p>I've seen plugins that do it are called "Add-On" but I do not want to use a plugin.</p>