declare
  l_data    clob;
  l_payment number;
  l_url     varchar2(1000) := 'https://ip_address:port/lksuengr/rest/getlastpayment?account=10200';
begin
  l_data := apex_web_service.make_rest_request(p_url => l_url, p_http_method => 'GET');
  select summa
    into l_payment
    from XMLTABLE('json/items/row' PASSING apex_json.to_xmltype(l_data) COLUMNS
                  summa number PATH 'summa');
   :p96_payment:=l_payment;
   EXCEPTION 
        WHEN no_data_found THEN
             :p96_payment:=999;
end;