Hot to access specific value inside a json string object


I have following ActionChain task

        name: "parse_payload"
        ref: "st2_viacbs_pack.stpayload"
            payload: "{{payload}}"
            output: "{{parse_payload.result|from_json_string}}"
        on-success: "c2"
        on-failure: "c4"

and on output i get:
“published”: {
“output”: “{‘st_enrichment’: ‘false’}”

In next task i want to get value of st_enrichment, how i can achieve that ? I tried

But it always return error, that object string doesn’t have st_enrichment or expected token is not valid.