how to receive dynamic link event in unity

 void Start() 
 {
     DynamicLinks.DynamicLinkReceived += OnDynamicLink;
 }
 
 // Display the dynamic link received by the application.
 void OnDynamicLink(object sender, EventArgs args) 
 {
     var dynamicLinkEventArgs = args as ReceivedDynamicLinkEventArgs;
     Debug.LogFormat("Received dynamic link {0}", dynamicLinkEventArgs.ReceivedDynamicLink.Url.OriginalString);
 }   

when i use above code i got bellow error in unity console

error CS0103: The name 'DynamicLinks' does not exist in the current context

error CS0103: The name 'OnDynamicLink' does not exist in the current context