Requirement: to create a pivot table which will show output like this:

My PL/SQL block looks like this:

DECLARE
    v_sql VARCHAR2(4000);
    v_months VARCHAR2(1000);
BEGIN
    -- Generate the list of months dynamically for the pivot clause
    FOR i IN 0..11 LOOP
        v_months := v_months ||''''|| TO_CHAR(ADD_MONTHS(SYSDATE, i), 'MonYYYY') || ''', ';
    END LOOP;

    -- Remove the trailing comma and space
    v_months := RTRIM(v_months, ', ');

    -- Construct the dynamic SQL for creating the table
    v_sql := 'CREATE TABLE dynamic_pivot_table_test AS ' ||
             'SELECT * FROM (' ||
             'SELECT part, TO_CHAR(begin_date, ''MonYYYY'') AS begin_date_YM, SUM(new_buy_units) AS SUM_UNITS ' ||
             'FROM one_mpbr ' ||
             'WHERE begin_date >= TRUNC(SYSDATE, ''MM'') ' ||
             'AND begin_date < ADD_MONTHS(TRUNC(SYSDATE, ''MM''), 12) ' ||
             'GROUP BY part, TO_CHAR(begin_date, ''MonYYYY'')) ' ||
             'PIVOT (SUM(SUM_UNITS) FOR begin_date_YM IN (' || v_months || '))';

    -- Print the dynamic SQL query
    DBMS_OUTPUT.PUT_LINE(v_sql);

    -- Execute the dynamic SQL query to create the table
    EXECUTE IMMEDIATE v_sql;
END;
/

Problem: this code is producing dynamic columns enclosed in single quotation mark as shown in the screenshot here:

I have to remove this mark also would be helpful if I can get Grand total column as well.