Data Action REST Proxy mapping nested JSON to Architect variables

Architect & Flows
1

Building a Data Action to call an external CRM endpoint. The REST Proxy action returns a 200 OK, but the JSON mapping step fails to populate the Architect variables. The response body is nested under a data key, like { "data": { "score": 95 } }. I tried mapping it to response.data.score in the JSON path, but the variable stays empty. Here is the mapping config I am using:

{
 "mappings": [
 {
 "sourceField": "response.data.score",
 "targetVariable": "leadScore"
 }
 ]
}

What is the correct syntax for accessing nested fields in the Data Action JSON mapper?