How to use the @pluralsight/ps-design-system-text.headingSizes.medium function in @pluralsight/ps-design-system-text

const ErrorPage = props => {
  const themeName = useTheme()
  const allProps = {
    ...props,
    themeName
  }
  return (
    <div>
      {allProps.iconId &amp;&amp; icons[allProps.iconId] &amp;&amp; (
        <div>{icons[allProps.iconId]()}</div>
      )}
      <div>
        
          <h1>{allProps.text}</h1>
        
      </div>
      <div>
        
          <h2>Error code: {allProps.code}</h2>
        
      </div>
      {allProps.href &amp;&amp; <button href="{allProps.href}">Contact support</button>}
      {allProps.action &amp;&amp; }
    </div>
  )
}
ErrorPage.propTypes = {