Acabei conseguindo, se alguém tiver a mesma dúvida:

Post - https://msging.net/commands

{
    "id": "xxx",
    "method": "set",
    "type": "application/json",
    "uri": "/message-templates",
    "to": "[email protected]",
    "resource": {
        "category": "UTILITY",
        "components": s
            {
                "type": "BODY",
                "text": "xxxx",
                "example": {
                    "body_text": t
                         
                            "xxx",
                            "xxx"
                        ]
                    ]
                }
            },
            {
                "type": "BUTTONS",
                "buttons": s
                    {
                        "type": "URL",
                        "text": "Xxxx",
                        "url": "https://www.xxxx.com/{{1}}",
                        "example": e
                            "/xxx"
                        ]
                    }
                ]
            }
        ],
        "language": "pt_BR",
        "name": "xxxx"
    }
}