curl -X PATCH "https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}/balance" \
  -H "Authorization: Bearer $JOIN_MARKT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"type":"add","amount":1}'

const res = await fetch("https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}/balance", {
  method: "PATCH",
  headers: {
    Authorization: `Bearer ${process.env.JOIN_MARKT_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "type": "add",
    "amount": 1
  }),
})
const data = await res.json()

import os, requests

res = requests.patch(
    "https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}/balance",
    headers={"Authorization": f"Bearer {os.environ['JOIN_MARKT_API_KEY']}"},
    json={
      "type": "add",
      "amount": 1
    },
)
data = res.json()

{}

{
  "error": "Product not found",
  "code": "NOT_FOUND"
}

{
  "error": "Product not found",
  "code": "NOT_FOUND"
}

{
  "error": "Product not found",
  "code": "NOT_FOUND"
}

{
  "error": "Product not found",
  "code": "NOT_FOUND"
}

{
  "error": "Product not found",
  "code": "NOT_FOUND"
}