import requests

payload = {
        "v": "5.102",
        "access_token": "64d2ccfb6b9319de58606ac7cbc59cc763d35887b6342d59d42845d9e7ef7d97c9f685e19078baf9fe7f7",
        "user_id": 209377620,
        "message": 'VKPay test',
        "keyboard": {
            "one_time": False,
            "buttons": [
                [{
                    "action": {
                        "type": "vkpay",
                        "hash": {
                            "action": 'pay-to-group',
                            "group_id": 170835296,
                            "aid": 10,
                            "amount": 1,
                            "data": {
                                "sender": 209377620
                            },
                            "description": 'test payment'
                        }
                    }
                }]
            ]
        }
    }

r = requests.post("https://api.vk.com/method/messages.send", data=payload)
print(r)