I am trying to get 2 values from the following data set however I get undefined values when I log the result.

{
    "categoryDescription": "NR",
    "bopCategoryCode": "Z",
    "forexBOPCategory": {
        "bopSubcategoryCode": "00",
        "rulingCode": "NA",
        "rulingOrSubcategoryDescription": "PS",
        "straightThroughProcess": "N",
        "categoryFlow": "I",
        "transferType": "I",
        "clientType": "NA",
        "sdaAllowed": "Y",
        "fcaAllowed": "N",
        "otherAllowed": "Y",
        "sdaRequireDocument": "Y",
        "documentCount": 1,
        "requiredDocumentCount": 0,
        "thirdPartyCapture": "N",
        "clientResidentialStatus": "Y",
        "bopPaymentRelation": "Y",
        "forexBOPCategoryDocumentsList": [
            {
                "bopCategoryCode": "ZZ1",
                "rulingCode": "NA",
                "documentDescription": "Document Desc",
                "documentShortDescription": "Document S Desc",
                "bopSubcategoryCode": "00"
            }
        ]
    }
}

From the above I need to get the rulingOrSubcategoryDescription and documentShortDescription

Here is my attempt:

this.formData.documentShortDescription = response.forexBOPCategory[0]?.forexBOPCategoryDocumentsList[0].documentShortDescription;
        
this.formData.rulingOrSubcategoryDescription = response.forexBOPCategory[0]?.rulingOrSubcategoryDescription;