Getting Android intent extras that were passed to the Unity app

I found an answer that gave me the code below:

 AndroidJavaClass UnityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
 AndroidJavaObject currentActivity = UnityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
 
 AndroidJavaObject intent = currentActivity.Call<AndroidJavaObject>("getIntent");
 bool hasExtra = intent.Call<bool>("hasExtra", "arguments");
 
 if (hasExtra)
 {
      Debug.Log("Extras");
 }

But it never seems to have extras when I am sure I am getting sent extras. Is there a certain point where the code above only works, or can I call it at any time (in an update or whatever) after the intent is called, and have it always contain the extras that were sent?

It could also be a problem with my manifest considering I don't know them that well. Do I have this set up correctly to receive extras? It comes from the second intent-filter. It starts (or continues) the app correctly, but I am not sure I set the manifest up correctly. (I changed some names below due to NDA).

 <?xml version="1.0" encoding="utf-8"?>
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.unity3d.player"
       android:installLocation="preferExternal"
     android:versionCode="5"
     android:versionName="1.05">
     <supports-screens
         android:smallScreens="true"
         android:normalScreens="true"
         android:largeScreens="true"
         android:xlargeScreens="true"
         android:anyDensity="true"/>
 
     <application
             android:theme="@style/UnityThemeSelector"
             android:icon="@drawable/app_icon"
         android:label="@string/app_name"
         android:debuggable="true">
         <activity android:name="com.unity3d.player.UnityPlayerActivity"
                   android:label="@string/app_name"
                   android:screenOrientation="portrait">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
             <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
 
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:mimeType="application/vnd.thing.app3d" />
             </intent-filter>
             <meta-data android:name="com.name.meta.type" android:value="type"/>
             <meta-data android:name="com.name.meta.category" android:value="print"/>
             <meta-data android:name="com.name.meta.label"  android:value="Some label"/>
             <meta-data android:name="com.name.meta.description" android:value="Some description"/>
             <meta-data android:name="com.name.meta.image" android:resource="@drawable/app_banner"/>
         </activity>
     </application>
 
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 </manifest>

Thank you for any help!