<p dir="auto">I am relatively new to flutter, but as far as I can tell, the google sign in flutter plugin does not allow you to authenticate with a custom back end using sign in options such as:<br>
<code class="notranslate">.requestIdToken(getString(R.string.server_client_id))</code></p>
<p dir="auto">I can login to my google account no issues, but my idToken is always null, which is something we would need to have for our back-end system.</p>
<p dir="auto">Am I completely misunderstanding how to use this?</p>
<h2 dir="auto">Steps to Reproduce</h2>
<p dir="auto">I started using Firebase Auth after I already had a custom OAuth impl in place, so in my previous app, I would authenticate the user on Firebase, but also request an ID Token from Google Signin <a href="https://developers.google.com/identity/sign-in/android/offline-access" rel="nofollow">https://developers.google.com/identity/sign-in/android/offline-access</a>.</p>
<p dir="auto">Is there currently a way to do this on <code class="notranslate">google_sign</code>in? On Android, I would do something like <code class="notranslate">SignIn.requestServerAuthCode(serverClientId)</code>.</p>
<h2 dir="auto">Logs</h2>
<p dir="auto">n/a</p>
<h2 dir="auto">Flutter Doctor</h2>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="[√] Flutter (Channel master, v0.2.12-pre.33, on Microsoft Windows [Version 10.0.14393], locale en-ZA)
    • Flutter version 0.2.12-pre.33 at C:\Users\&lt;me&gt;\flutter
    • Framework revision ea30c95dc9 (2 days ago), 2018-04-13 17:02:14 -0700
    • Engine revision 76cb311d9c
    • Dart version 2.0.0-dev.47.0.flutter-f76dad0adc

[√] Android toolchain - develop for Android devices (Android SDK 27.0.3)
    • Android SDK at C:\Users\&lt;me&gt;\AppData\Local\Android\sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-27, build-tools 27.0.3
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
    • All Android licenses accepted.

[√] Android Studio (version 3.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 23.0.2
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] IntelliJ IDEA Community Edition (version 2017.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2017.3.4
    • Flutter plugin version 23.0.2
    • Dart plugin version 173.4700

[√] IntelliJ IDEA Ultimate Edition (version 2018.1)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2018.1
    • Flutter plugin version 23.1.3
    • Dart plugin version 181.4203.498

[√] VS Code, 64-bit edition (version 1.22.1)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Dart Code extension version 2.11.2

[√] Connected devices (1 available)
    • SM G610F • 5203f84b5378a381 • android-arm • Android 7.0 (API 24)

• No issues found!"><pre class="notranslate"><code class="notranslate">[√] Flutter (Channel master, v0.2.12-pre.33, on Microsoft Windows [Version 10.0.14393], locale en-ZA)
    • Flutter version 0.2.12-pre.33 at C:\Users\&lt;me&gt;\flutter
    • Framework revision ea30c95dc9 (2 days ago), 2018-04-13 17:02:14 -0700
    • Engine revision 76cb311d9c
    • Dart version 2.0.0-dev.47.0.flutter-f76dad0adc

[√] Android toolchain - develop for Android devices (Android SDK 27.0.3)
    • Android SDK at C:\Users\&lt;me&gt;\AppData\Local\Android\sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-27, build-tools 27.0.3
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
    • All Android licenses accepted.

[√] Android Studio (version 3.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 23.0.2
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] IntelliJ IDEA Community Edition (version 2017.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2017.3.4
    • Flutter plugin version 23.0.2
    • Dart plugin version 173.4700

[√] IntelliJ IDEA Ultimate Edition (version 2018.1)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2018.1
    • Flutter plugin version 23.1.3
    • Dart plugin version 181.4203.498

[√] VS Code, 64-bit edition (version 1.22.1)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Dart Code extension version 2.11.2

[√] Connected devices (1 available)
    • SM G610F • 5203f84b5378a381 • android-arm • Android 7.0 (API 24)

• No issues found!
</code></pre></div>