curl --request PUT \
  --url https://api.virtuoussoftware.com/api/RecurringGift/{recurringGiftId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "startDate": "<dateTime>",
  "frequency": "Weekly|Bimonthly|Monthly|Quarterly|Semiannually|Annually|Biennially",
  "amount": "<double>",
  "nextExpectedPaymentDate": "<dateTime>",
  "anticipatedEndDate": "<dateTime>",
  "thankYouDate": "<dateTime>",
  "segmentId": "<integer>",
  "automatedPayments": "<boolean>",
  "trackPayments": "<boolean>",
  "isPrivate": "<boolean>",
  "designations": [
    {
      "projectId": "<integer>",
      "amountDesignated": "<double>"
    },
    {
      "projectId": "<integer>",
      "amountDesignated": "<double>"
    }
  ],
  "customFields": [
    {
      "name": "<string>",
      "value": "<string>",
      "displayName": "<string>"
    },
    {
      "name": "<string>",
      "value": "<string>",
      "displayName": "<string>"
    }
  ]
}
'

{
  "id": "<integer>",
  "transactionSource": "<string>",
  "transactionId": "<string>",
  "contactId": "<integer>",
  "startDate": "<dateTime>",
  "amount": "<double>",
  "frequency": "<string>",
  "anticipatedEndDate": "<dateTime>",
  "cancelDateTimeUtc": "<dateTime>",
  "createDateTimeUtc": "<dateTime>",
  "createdByUser": "<string>",
  "modifiedDateTimeUtc": "<dateTime>",
  "modifiedByUser": "<string>",
  "segmentId": "<integer>",
  "segment": "<string>",
  "segmentUrl": "<string>",
  "automatedPayments": "<boolean>",
  "trackPayments": "<boolean>",
  "isPrivate": "<boolean>",
  "status": "<string>",
  "nextExpectedPaymentDate": "<dateTime>",
  "designations": [
    {
      "projectId": "<integer>",
      "project": "<string>",
      "projectUrl": "<string>",
      "amountDesignated": "<double>",
      "projectCode": "<string>"
    },
    {
      "projectId": "<integer>",
      "project": "<string>",
      "projectUrl": "<string>",
      "amountDesignated": "<double>",
      "projectCode": "<string>"
    }
  ],
  "customFields": [
    {
      "name": "<string>",
      "value": "<string>",
      "displayName": "<string>"
    },
    {
      "name": "<string>",
      "value": "<string>",
      "displayName": "<string>"
    }
  ]
}