title: How to put a condition to NavigationLink? SWIFTUI
body: <p>I would like to put a condition to the NavigationLink. </p>
  
  <p>I have two variable, and the NavigationLink as below. </p>
  
  <pre><code>  @State var score = 0
    @State var target = 10
  
  NavigationLink(destination: level2()) {     
    Text("Next Level")
   }
  </code></pre>
  
  <p>Is there a way to let the user go to the next level if the score is bigger than the target?</p>
  
  <p>Thanks.</p>