title: How can i make textfield with hyphen at certain places of input number in flutter
body: <p>I am making the UI in which i have to show the input text field like this:</p>
  <p><a href="https://i.stack.imgur.com/11Omk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/11Omk.jpg" alt="enter image description here" /></a></p>
  <p>I try to make it like this but unable to make as i am new to flutter. Is there any kind of widget that will fulfill this requirement in flutter or you can guide me how can i make this one widget.</p>