title: getting error when try to build production with ionic
body: <p>I am getting error when try to build production for the pwa in ionic.</p>
  
  <p>i have attach screenshot of error, ionic and npm version configuration, and also app module file.</p>
  
  <p><a href="https://i.stack.imgur.com/TwigT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TwigT.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/FwPKq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FwPKq.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/RImUS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RImUS.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/2erx0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2erx0.png" alt="enter image description here"></a></p>