Error making UTL_HTTP request. ORA-28759: failure to open file

When doing request to given endpoint , the following error occurs

CREATEORREPLACEPROCEDURECALL_REST_WEBSERV_POST_METHODASV_WLT_DIRECTORYVARCHAR2(4000):='file:/oradisk/app/oracle/product/11.2.0.4/db_1/wallet/Cert_occ_17112019.p7b';V_WLT_PASSWORDVARCHAR2(40):='testeosc1';V_REQUESTUTL_HTTP.REQ;V_RESPONSEUTL_HTTP.RESP;V_TEXTVARCHAR2(2000);CONTENTVARCHAR2(4000):='{"values": [
            {
                "key": "occ-env",
                "value": "https://admin-admin",
                "enabled": true
            },
            {
                "key": "occ-user",
                "value": "meuusuario@tofodido",
                "enabled": true
            },
            {
                "key": "occ-password",
                "value": "xxxxxxx",
                "enabled": true
            },
            {
                "key": "occ-key",
                "value": "000000",
                "description": {
                    "content": "",
                    "type": "text/plain"
                },
                "enabled": true
             }
         ],
    }' ;

BEGIN

    DBMS_OUTPUT.PUT_LINE('Passou 1'); 

    UTL_HTTP.SET_WALLET(V_WLT_DIRECTORY
        ,V_WLT_PASSWORD);

    DBMS_OUTPUT.PUT_LINE('Passou 2'); 

    V_REQUEST := UTL_HTTP.BEGIN_REQUEST('https://meu_endpointblablabla/'
        ,'POST'
        ,'HTTP/1.1');

    DBMS_OUTPUT.PUT_LINE('Passou 3'); 


    UTL_HTTP.SET_HEADER(V_REQUEST, 'Content-Type', 'application/x-www-form-urlencoded');
    UTL_HTTP.SET_HEADER(V_REQUEST, 'Authorization', 'OAuth');
    UTL_HTTP.SET_HEADER(V_REQUEST, 'Content-Length', LENGTH(CONTENT));

    UTL_HTTP.WRITE_TEXT(V_REQUEST, CONTENT);

    V_RESPONSE := UTL_HTTP.GET_RESPONSE(V_REQUEST);

    DBMS_OUTPUT.PUT_LINE('Resposta status : ' || V_RESPONSE.STATUS_CODE);
    DBMS_OUTPUT.PUT_LINE('Resposta rasão: '   || V_RESPONSE.REASON_PHRASE);


    LOOP
        BEGIN
            UTL_HTTP.READ_TEXT(V_RESPONSE, V_TEXT);
            DBMS_OUTPUT.PUT_LINE(V_TEXT);
            EXCEPTION
                WHEN UTL_HTTP.END_OF_BODY THEN
                    NULL;
                END;

        EXIT WHEN V_TEXT IS NULL;
    END LOOP;

    UTL_HTTP.END_RESPONSE(V_RESPONSE);
END; 

Has anyone ever encountered this problem? Thank you.