根据Firebase文档，要在成功登录时获取OAuth访问令牌，我们可以从getCredential（）方法获取，如下所示：验证结果.获取凭证（）.获取访问令牌（）
代码：根据火源：

firebaseAuth
.startActivityForSignInWithProvider(/* activity= */ this, provider.build())
.addOnSuccessListener(
    new OnSuccessListener<AuthResult>() {
      @Override
      public void onSuccess(AuthResult authResult) {
        // User is signed in.
        // IdP data available in
        // authResult.getAdditionalUserInfo().getProfile().
        // The OAuth access token can also be retrieved:
        // authResult.getCredential().getAccessToken().
      }
    })
.addOnFailureListener(
    new OnFailureListener() {
      @Override
      public void onFailure(@NonNull Exception e) {
        // Handle failure.
      }
    });

但是，当我尝试像这样访问令牌时，它只是简单地说该方法不存在。

pendingResultTask
    ?.addOnSuccessListener { authResult ->
        val username = authResult.additionalUserInfo?.username
        val accessToken = authResult.getCredential().getAccessToken()

        Toast.makeText(
            activity,
            "username: $username, accessToken: $accessToken",
            Toast.LENGTH_LONG
        ).show()
        navigateToHomeScreen()
    }
    ?.addOnFailureListener { exception ->
        Toast.makeText(
            activity,
            "Something Went Wrong: ${exception.message}",
            Toast.LENGTH_LONG
        ).show()
    }

在这段代码中，我不能使用getAccessToken()方法，错误：未解析的引用
为什么我无法访问getAccessToken()方法？