Record a customer retention activity

curl --request POST \
  --url https://www.myshop.com/apps/subscriptions/cp/api/customer-retention-activities \
  --header 'Content-Type: application/json' \
  --data '
{
  "id": 123,
  "shop": "<string>",
  "contractId": 123,
  "activityOn": "2023-11-07T05:31:56Z",
  "retentionAction": "<string>",
  "cancellationReason": "<string>",
  "discountApplied": "<string>",
  "additionalInfo": "<string>"
}
'

{
  "id": 123,
  "shop": "<string>",
  "contractId": 123,
  "activityOn": "2023-11-07T05:31:56Z",
  "retentionAction": "<string>",
  "cancellationReason": "<string>",
  "discountApplied": "<string>",
  "additionalInfo": "<string>"
}