Firebase Error: Auth error from APNS or Web Push Service

After running the following line in node-js:

import * as admin from "firebase-admin";
import * as serviceAccount from "../../firebase_service_account_key.json";

const app = admin.initializeApp({
  credential: admin.credential.cert(serviceAccount as any),
  databaseURL: "https://my-app-path.firebaseio.com"
});

admin.messaging().send({
    token: "known-good-token",
    notification: {
        title: "Test Push Note",
        body: "Here is some text"
    }
});

I'm getting the error:

Error: Auth error from APNS or Web Push Service 
Raw server response: 
"{
  "error":{
    "code":401,
    "message":"Auth error from APNS or Web Push Service",
    "status":"UNAUTHENTICATED",
    "details"[
      {
        "@type":"type.googleapis.com/google.firebase.fcm.v1.FcmError",
        "errorCode":"THIRD_PARTY_AUTH_ERROR"
      },
      {
        "@type":"type.googleapis.com/google.firebase.fcm.v1.ApnsError",
        "statusCode":403,
        "reason":"InvalidProviderToken"
      }
    ]
  }
}"

I've added an "APNs Authentication Key" to my ios project under the Settings > Cloud Messaging section of Firebase. I've also properly downloaded and imported my service account json file.

In terms of research, I've tried looking up the errors.

• For the InvalidProviderToken error, this answer seems to indicate I'm using an old token. This is totally possible, but the logs on my app and database appear to match, so it seems off.

• As for the THIRD_PARTY_AUTH_ERROR, google gave me no hits. The closest thing I found was this, and the following text might be the culprit (EDIT: it's not the issue):

auth/unauthorized-domain

Thrown if the app domain is not authorized for OAuth operations for your Firebase project. Edit the list of authorized domains from the Firebase console.

Does anyone have anymore details on this error which might help me get to the bottom of it?

This error arises if your app setup for iOS has an error in any one of the following:

Found in Settings > General > Your Apps > iOS Apps:

• App Store ID
• Bundle ID
• Team ID

When adding an APNs key (Uploading to Cloud Messaging > APNs Authentication Key):

• Team ID (should auto set based off ios app info above)
• Key Id (often is in the name of the key, best to grab when creating it)