Simple curl to send a notification to firebase with a deviceID.

firebase-notification-with-curl.sh

curl -d '{
  "to": DEVICE_ID,
   "notification": {
     "title" : " This is my title new ",
     "body" : " This is the body of my message "
   }
}' \
-i -H "Application/json" \
-H "Content-type: application/json" \
-H "Authorization: key=YOUR_AUTH_KEY \
-X POST https://fcm.googleapis.com/fcm/send

official document : Firebaes

Curl

curl --location 'https://fcm.googleapis.com/v1/projects/product-name/messages:send' \
--header 'Content-type: application/json' \
--header 'Authorization: Bearer .... need to generate auth token ' \
--data '{
   "message":{
      "token":" DEVICE_ID",
      "notification":{
        "body":"If you need help to create Auth token from a service account (firebase) please contact +8801722835935 whatsApps",
        "title":"FCM Message"
      }
   }
}