title: Extract OTP from message and show only OTP value in react native
body: <p>I have a string let's say : <code>Rishav app OTP is : 1232</code></p>
  
  <p>I also have the regex : <code>/^\b\d{ 4}\b/</code></p>
  
  <p>Somehow when I test and match the regex with the string it shows me false.
  But when I test the regex online it highlights the OTP. </p>
  
  <p>Can someone please help me with the code of getting only the OTP number?</p>