curl --request POST \
  --url https://mainnet.gomaestro-api.org/v1/contracts/subscription/initSubscription \
  --header 'Content-Type: application/json' \
  --header 'api-key: <api-key>' \
  --data '
{
  "service_nft_tn": "<string>",
  "account_nft_tn": "<string>",
  "subscription_fee": {
    "policy_id": "<string>",
    "asset_name": "<string>"
  },
  "total_subscription_fee": "<string>",
  "subscription_start": "<string>",
  "subscription_end": "<string>",
  "interval_length": "<string>",
  "interval_amount": "<string>",
  "num_intervals": "<string>",
  "last_claimed": "<string>",
  "penalty_fee": {
    "policy_id": "<string>",
    "asset_name": "<string>"
  },
  "penalty_fee_qty": "<string>",
  "minimum_ada": "<string>"
}
'

{
  "cbor_hex": "<string>",
  "tx_hash": "<string>"
}