title: IE array.flat() Object doesn't support property or method 'flat'
body: <p>When accessing my website from google chrome everything works fine(also on mobile).
  but when trying to access from edge  \ mobile normal browser(not google chrome)
  i get</p>
  
  <pre><code>TypeError: Object doesn't support property or method 'flat'
  </code></pre>
  
  <p>trying to access a function .flat of array.</p>
  
  <p>turns out that it dosent exist on the proto at all.
  what can i do with it?
  the childs array is defined as </p>
  
  <pre><code>`let childs = [];`
  </code></pre>
  
  <p>(using react for front end)<a href="https://i.stack.imgur.com/Vfgtk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Vfgtk.png" alt="enter image description here"></a></p>