Question: I am using firebase phone auth for the very first time and I see captcha verification is must proceed with the process, as per firebase official documentation. Though it serves a good purpose, but sometimes it becomes very bad for the user experience when it starts asking about the road signs, bridges and all. Is there a way to directly skip to the verification code right after getting user's number? As per the documentation, the code is mentioned below. Thanks.

```
var phoneNumber = getPhoneNumberFromUserInput();
var appVerifier = window.recaptchaVerifier;
firebase.auth().signInWithPhoneNumber(phoneNumber, appVerifier)
    .then(function (confirmationResult) {
      // SMS sent. Prompt user to type the code from the message, then sign the
      // user in with confirmationResult.confirm(code).
      window.confirmationResult = confirmationResult;
    }).catch(function (error) {
      // Error; SMS not sent
      // ...
});

var code = getCodeFromUserInput();
confirmationResult.confirm(code).then(function (result) {
  // User signed in successfully.
  var user = result.user;
  // ...
}).catch(function (error) {
  // User couldn't sign in (bad verification code?)
  // ...
});

```

Answer: 
use size: "normal" to size: "invisible" 

```
 window.recaptchaVerifier = new firebase.auth.RecaptchaVerifier(
    "recaptcha-container",
    {
      size: "invisible",
      callback: function(response) {
        submitPhoneNumberAuth();
      }
    }
  );

```
Actually you can't. But, some of the devices it does not work. Instead, setup Safety and enable API key. Then back to your project setting in Firebase and copy and paste SHA-25 from Android Gradle to there if it does not exist. In this manner, in app browser redirecting will be no more irritating to you...