CreateSubscriptionPlan

{
    "description": "string",
    "reference": "string",
    "amount": {
        "units": 0,
        "currencyCode": "GBP"
    },
    "frequency": "weekly",
    "numberOfPayments": 1,
    "dataCollection": [
        "name"
    ],
    "taxes": [
        {
            "name": "string",
            "inclusive": true,
            "rate": "string"
        }
    ],
    "returnUrl": "http://example.com"
}