Push Notifications: APNS 404 {"reason":"BadPath"}

Hello everyone!

I am trying to implement push notifications in my WatchOS app. I have created the delegate class that handles the registration for remote notifications and that allows me to obtain the device token. Then I take the token and send it to Firebase, like this:

func didRegisterForRemoteNotifications(withDeviceToken deviceToken: Data) {

    FirebaseApp.configure()
    var ref: DatabaseReference!

    ref = Database.database().reference().ref.child("/")

    let tokenParts = deviceToken.map { data in String(format: "%02.2hhx", data) }
    let token = tokenParts.joined()

     if let userID = UserDefaults.standard.object(forKey: "id") as? String {

        ref.child("users/\(userID)/token").setValue(token)

    }
}

Then I am using a Python Script to communicate with APNS. I am using the http library to get access to HTTP2. This is what I have got:

payload = {
   "aps" : {
      "alert" : {
         "title" : "Hello Push",
         "message": "This is a notification!"
      },
      "category": "myCategory"
   }
}

dev_server = "https://api.sandbox.push.apple.com:443"
device_token = "9fe2814b6586bbb683b1a3efabdbe1ddd7c6918f51a3b83e90fce038dc058550"

headers = {
    'method': 'POST',
    'path': '/3/device/{}'.format(device_token),
    'autorization': 'bearer' + 'provider_token',
    'apns-push-type': 'myCategory',
    'apns-expiration': '0',
    'apns-priority': '10',
}

async def test():
    async with httpx.AsyncClient(http2=True) as client:

        client = httpx.AsyncClient(http2=True)
        r = await client.post(dev_server, headers=headers, data=payload)
        print(r.text)

asyncio.run(test())

I have also downloaded the .p8 auth key file. But I don't really understand from the Apple Documentation what I have to do with it.

What is the provider token in the headers?

Am I doing the right thing with the token I receive from didRegisterForRemoteNotifications?