title: Can't directly open whatsapp chat group invite
body: <p>I need to open a whatsapp chat group link invite (<a href="https://chat.whatsapp.com/############" rel="nofollow noreferrer">https://chat.whatsapp.com/############</a>) from my flutter app without opening the browser first. just using url_launcher and launch('<a href="https://chat.whatsapp.com/############" rel="nofollow noreferrer">https://chat.whatsapp.com/############</a>') works on android, but on IOS it opens Safari first.</p>
  
  <p>I had the same problem for telegram, but I found this: tg://join?invite=XXXXXX, which I'm 99% sure it will work for IOS, but I didn't find anything similar for Whatsapp, except for Whatsapp://send= but it doesn't work to open the invite</p>