One API Call.
Notifications Everywhere.

import requests

response = requests.post(
    "https://api.notificationsbot.com/events",
    headers={
        "Authorization": "Bearer YOUR_API_KEY",
        "Content-Type": "application/json"
    },
    json={
        "title": "Payment received",
        "message": "User #4821 upgraded to Pro plan ($5/mo)",
        "channel_code": "my_saas_app",
        "group_codes": ["billing"],
        "metadata": {
            "user_id": "4821",
            "plan": "pro",
            "amount": 5.00
        }
    }
)

print(response.json())

const response = await fetch(
  "https://api.notificationsbot.com/events",
  {
    method: "POST",
    headers: {
      "Authorization": "Bearer YOUR_API_KEY",
      "Content-Type": "application/json"
    },
    body: JSON.stringify({
      title: "Payment received",
      message: "User #4821 upgraded to Pro plan ($5/mo)",
      channel_code: "my_saas_app",
      group_codes: ["billing"],
      metadata: {
        user_id: "4821",
        plan: "pro",
        amount: 5.00
      }
    })
  }
);

const data = await response.json();
console.log(data);

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "net/http"
)

func main() {
    body, _ := json.Marshal(map[string]interface{}{
        "title":        "Payment received",
        "message":      "User #4821 upgraded to Pro plan ($5/mo)",
        "channel_code": "my_saas_app",
        "group_codes":  []string{"billing"},
        "metadata": map[string]interface{}{
            "user_id": "4821",
            "plan":    "pro",
            "amount":  5.00,
        },
    })

    req, _ := http.NewRequest("POST",
        "https://api.notificationsbot.com/events",
        bytes.NewBuffer(body))
    req.Header.Set("Authorization", "Bearer YOUR_API_KEY")
    req.Header.Set("Content-Type", "application/json")

    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()
    fmt.Println("Status:", resp.Status)
}

$ch = curl_init("https://api.notificationsbot.com/events");

curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer YOUR_API_KEY",
        "Content-Type: application/json"
    ],
    CURLOPT_POSTFIELDS => json_encode([
        "title" => "Payment received",
        "message" => "User #4821 upgraded to Pro plan (\$5/mo)",
        "channel_code" => "my_saas_app",
        "group_codes" => ["billing"],
        "metadata" => [
            "user_id" => "4821",
            "plan" => "pro",
            "amount" => 5.00
        ]
    ])
]);

$response = curl_exec($ch);
curl_close($ch);

echo $response;