SQL failed to run. Not sure how to fix.

create or replace function fetch_users(user_id text)
returns json as
$func$
  declare @cached_array array
  declare @result json

  select @cached_array = cached 
  from public.kisis_cache 
  where tg_id = $1;

  select @result = *
  from public.kisis_cache 
  where tg_id not in cached_array and status = 'active';

  return @result
$func$
language sql;

create or replace function fetch_users(user_id text)
returns json as
$func$
  declare @cached_array array
  declare @result json

  select @cached_array = cached 
  from public.kisis_cache 
  where tg_id = $1;

  select @result = *
  from public.kisis_cache 
  where tg_id not in cached_array and status = 'active';

  return @result
$func$
language sql;