Workflow: Mattermost Webhook Automate

{
    "nodes": [
        {
            "name": "Webhook",
            "type": "n8n-nodes-base.webhook",
            "position": [
                590,
                400
            ],
            "webhookId": "822cce61-ff5f-4cea-b8ba-1822651786e3",
            "parameters": {
                "path": "822cce61-ff5f-4cea-b8ba-1822651786e3",
                "options": [],
                "httpMethod": "POST"
            },
            "typeVersion": 1
        },
        {
            "name": "Set",
            "type": "n8n-nodes-base.set",
            "position": [
                780,
                400
            ],
            "parameters": {
                "values": {
                    "string": [
                        {
                            "name": "amudhan",
                            "value": "n8n-rocks"
                        }
                    ]
                },
                "options": [],
                "keepOnlySet": true
            },
            "typeVersion": 1
        },
        {
            "name": "Mattermost",
            "type": "n8n-nodes-base.mattermost",
            "position": [
                990,
                400
            ],
            "parameters": {
                "message": "=Join me in a video call:",
                "channelId": "={{$node[\"Webhook\"].json[\"body\"][\"channel_id\"]}}",
                "attachments": [
                    {
                        "title": "=https:\/\/whereby.com\/{{$json[$node[\"Webhook\"].json[\"body\"][\"user_name\"]]}}",
                        "title_link": "=https:\/\/whereby.com\/{{$json[$node[\"Webhook\"].json[\"body\"][\"user_name\"]]}}"
                    }
                ],
                "otherOptions": []
            },
            "credentials": {
                "mattermostApi": "mm_creds"
            },
            "typeVersion": 1
        }
    ],
    "connections": {
        "Set": {
            "main": [
                [
                    {
                        "node": "Mattermost",
                        "type": "main",
                        "index": 0
                    }
                ]
            ]
        },
        "Webhook": {
            "main": [
                [
                    {
                        "node": "Set",
                        "type": "main",
                        "index": 0
                    }
                ]
            ]
        }
    }
}