title: How to access dynamic variable names in twig?
body: <p>I have some variables in twig like</p>
  
  <pre><code>placeholder1
  placeholder2
  placeholderx
  </code></pre>
  
  <p>To call them, I am looping through the array of objects "invoices"</p>
  
  <pre><code>{% for invoices as invoice %}
      need to display here the placeholder followed by the invoice id number
      {{ placeholedr1 }}
  </code></pre>