curl --request GET \
  --url https://services.leadconnectorhq.com/locations/{locationId}/customValues/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Version: <version>'

{
  "customValue": {
    "id": "rWQ709Pb62syqGLceg1x",
    "name": "Custom Field",
    "fieldKey": "{{ custom_values.custom_field }}",
    "value": "Value",
    "locationId": "rWQ709Pb6dasyqGLceg1x"
  }
}