curl -X GET "https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}" \
  -H "Authorization: Bearer $JOIN_MARKT_API_KEY"

const res = await fetch("https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}", {
  method: "GET",
  headers: {
    Authorization: `Bearer ${process.env.JOIN_MARKT_API_KEY}`,
  },
})
const data = await res.json()

import os, requests

res = requests.get(
    "https://dash.joinmarkt.com/api/merchant/v1/stores/STORE_ID/customers/{customerKey}",
    headers={"Authorization": f"Bearer {os.environ['JOIN_MARKT_API_KEY']}"},
)
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"
}