curl --request POST \
  --url https://vpn.bserv.dev/api/v1/customer/add-note \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --header 'token: <api-key>' \
  --data id=123 \
  --data 'note=<string>'

{
  "success": true,
  "user_id": 48,
  "message": "Note added successfully."
}