Bạn chạy lệnh : 

python3 -m pip install -r requirements.txt 

để cài đặt các gói cần thiết để chạy app .

Trong worker chạy lệnh thay :

trong config o giao dien python manager them : worker_class = 'uvicorn.workers.UvicornWorker' thay cho worker_class = "sync" như sau

worker_class = 'sync' bằng
worker_class = 'uvicorn.workers.UvicornWorker'

Và đoạn code main.py

from fastapi import FastAPI, HTTPException
from typing import List  # Đảm bảo dòng này nằm trên cùng nếu chưa có
import asyncio
from pydantic import BaseModel
from google.auth.transport.requests import Request
from google.oauth2 import service_account
from datetime import datetime, timedelta
import os
import httpx
import uvicorn

app = FastAPI()

CREDENTIAL_PATH = os.path.join(os.getcwd(), "firebase-adminsdk.json")
SCOPES = ["https://www.googleapis.com/auth/firebase.messaging"]
PROJECT_ID = "truyenvideo-3eb09"

# Token cache
_token_cache = {
    "token": None,
    "expire": datetime.utcnow()
}

def get_access_token():
    now = datetime.utcnow()
    if _token_cache["token"] and _token_cache["expire"] > now:
        return _token_cache["token"]

    credentials = service_account.Credentials.from_service_account_file(
        CREDENTIAL_PATH, scopes=SCOPES
    )
    credentials.refresh(Request())
    _token_cache["token"] = credentials.token
    _token_cache["expire"] = now + timedelta(minutes=40)  # token sống ~60 phút
    return credentials.token

class FCMRequest(BaseModel):
    token: str
    title: str
    body: str
    image: str = None
    url: str = None

class FCMMultiRequest(BaseModel):
    tokens: List[str]
    title: str
    body: str
    image: str = None
    url: str = None

@app.get("/")
def root():
    return {"status": "OK"}

# $response = Http::post('http://127.0.0.1:8000/send-fcm', [
#     'token' => 'flMcjT6Yh0afxHlezVBx7g:APA91bEebU4AAnl_f9Jlf1ZuxkFJYdDlnGJStDBoJapjOZuDIwjob_eqWYDvCBMS_jp-z2C-LDnipVZ0QX4CUCtXmMGobgu485Y01oSQpKd6PS8cpLcQhGs',
#     'title' => 'Hello!',
#     'body' => 'Đây là thông báo từ FastAPI',
#     'image' => 'https://i3.ytimg.com/vi/OiMqLZlB8DY/maxresdefault.jpg',
#     'url'   => 'https://www.youtube.com/watch?v=w0Dapj9kKS0&ab_channel=H%C5%A9Mu%E1%BB%91iAudio',
# ]);
#
# // Kiểm tra phản hồi
# if ($response->successful()) {
#     dd($response->json());
# } else {
#     dd($response->status(), $response->body());
# }

@app.post("/send-fcm")
async def send_fcm(req: FCMRequest):
    try:
        access_token = get_access_token()

        fcm_url = f"https://fcm.googleapis.com/v1/projects/{PROJECT_ID}/messages:send"
        headers = {
            "Authorization": f"Bearer {access_token}",
            "Content-Type": "application/json",
        }

        message = {
            "message": {
                "token": req.token,
                "data": {
                    "title": req.title,
                    "body": req.body,
                    "image": req.image or "",
                    "url": req.url or "",
                },
            }
        }

        async with httpx.AsyncClient() as client:
            response = await client.post(fcm_url, headers=headers, json=message)

        if response.status_code != 200:
            return {
                "status": "failed",
                "status_code": response.status_code,
                "error": response.text,
            }

        return {"status": "success", "response": response.json()}

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

async def send_single_token(token: str, payload: dict, access_token: str):
    fcm_url = f"https://fcm.googleapis.com/v1/projects/{PROJECT_ID}/messages:send"
    headers = {
        "Authorization": f"Bearer {access_token}",
        "Content-Type": "application/json",
    }

    message = {
        "message": {
            "token": token,
            "data": payload,
        }
    }

    async with httpx.AsyncClient() as client:
        response = await client.post(fcm_url, headers=headers, json=message)
        return {
            "token": token,
            "status_code": response.status_code,
            "response": response.json() if response.status_code == 200 else response.text
        }

# send more tokens
# $response = Http::post('http://127.0.0.1:8000/send-multiple-fcm', [
#     'tokens' => [
#         'fcm_token_1',
#         'fcm_token_2',
#         'fcm_token_3',
#     ],
#     'title' => '🔥 Tin nóng',
#     'body' => 'Nội dung mới đã cập nhật!',
#     'image' => 'https://i.imgur.com/banner.png',
#     'url' => 'https://truyenvideo.com'
# ]);


@app.post("/send-multiple-fcm")
async def send_multiple_fcm(req: FCMMultiRequest):
    try:
        access_token = get_access_token()
        payload = {
            "title": req.title,
            "body": req.body,
            "image": req.image or "",
            "url": req.url or "",
        }
        batch_size = 500
        all_results = []

        for i in range(0, len(req.tokens), batch_size):
            batch = req.tokens[i:i + batch_size]
            tasks = [send_single_token(token, payload, access_token) for token in batch]
            results = await asyncio.gather(*tasks, return_exceptions=True)

            for result in results:
                if isinstance(result, Exception):
                    all_results.append({
                        "token": "unknown",
                        "status_code": 500,
                        "response": str(result)
                    })
                else:
                    all_results.append(result)

            # Tuỳ chọn: nghỉ giữa các batch nếu cần
            await asyncio.sleep(0.2)  # giảm tải nếu cần

        return {
            "sent_count": len(all_results),
            "success": [r for r in all_results if r["status_code"] == 200],
            "failed": [r for r in all_results if r["status_code"] != 200],
        }

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

if __name__ == "__main__":
    uvicorn.run("main:app", host="127.0.0.1", port=8000, reload=True)

Link download : https://drive.google.com/file/d/16YlX2y2vXiDEXL62wfHdZBG-4Sqcb-nb/view?usp=sharing