title: Input amount for a PayPal Buy Now button?
body: <p>I'd like the user to be able to type the amount they wish to pay into a text box, then click "Buy Now", and that amount will be charged through PayPal. How do I go about creating a PayPal button like this?</p>
  
  <p><img src="https://i.stack.imgur.com/FdcV4.jpg" alt="enter image description here"></p>