I need help with a JavaScript function that I don't know how to implement.
I need to make a store for a school project, and I need the price to dynamically update when adding / removing quantities.
Here is a picture of the store, the +/- button work correctly and all I just need to update the price in the add button.
I tried writing a function that will take the price below the name of the product and multiply it by the value in the quantity box but it's not working.

<button class="buttonshad buttonstyling bg-primary text-light mx-5">Add <a id="changingprice">$6.99</a></button>

Here is my JavaScript function for increasing and decreasing:

  function increaseValue() {
    value = parseInt(document.getElementById('number').value, 10);
    value = isNaN(value) ? 0 : value;
    value++;
    document.getElementById('number').value = value;
  }

  function decreaseValue() {
    value = parseInt(document.getElementById('number').value, 10);
    value = isNaN(value) ? 0 : value;
    value < 1 ? value = 1 : '';
    value--;
    document.getElementById('number').value = value;
  }

Basically what I need is to update the price in the button when I add / remove quantity!