send message to WhatsApp Group using WhatsApp API

Step 1 : Create new WhatsApp group

you can create groups through your Mobile and add members for Sending messages to these groups.

Step 2 : Get WhatsApp groups ID

To be able to send messages to a group, you must know the group ID, you can make GET request or via ultramsg documentation :

EXAMPLE JSON RESPONSE :

[
  {
    "id": "[email protected]",
    "name": "group name",
    "isGroup": true,
    "groupMetadata": {
      "description": "",
      "owner": "[email protected]",
      "creation": 1511456874,
      "participants": [
        {
          "id": "[email protected]",
          "isAdmin": false,
          "isSuperAdmin": false
        },
        {
          "id": "[email protected]",
          "isAdmin": true,
          "isSuperAdmin": false
        }
      ]
    },
    "last_time": 1637644088,
    "archived": true,
    "pinned": false,
    "isMuted": false
  }
]

Now we have the group id: [email protected]

Step 3 : Send message to group

https://api.ultramsg.com/{INSTANCE_ID}/messages/chat
Parameterdescription
toGroup ID, We’ve got In the second step: 10172127175-[email protected]
bodyMessage text, UTF-8 or UTF-16 string with emoji
Max length: 4096 char.
send message to WhatsApp Group - Ultramsg

you can read this article to send WhatsApp messages using PHP language.