[Solved] Oracle Error: ora-00923 from keyword not found where expected

Hi! Below script show another error:

Error: ora-00923 from keyword not found where expected

WITH cte_month AS
(SELECT row_number() OVER(PARTITION BY to_char(r."balance_date", 'Month'), to_char(r."balance_date", 'Year') ORDER BY "balance_date" DESC) rownum,
         arrears_in_days AS "arrears_in_days",
         balance_date AS "balance_date",
         acct_id AS "acct_id"
    FROM report r
   where r."acct_id" = '11002140008598'
     and (to_char(r."balance_date", 'D')) not in (6, 7))
 
select xmlserialize(content "arrears_in_days" as clob)
from ( select * from cte_month )
pivot xml
(
      max("arrears_in_days")
      for ("balance_date")
      in (select distinct "balance_date" from cte_month)
);