Error occur when Column Total at the end of SQL Pivot query

I have generated the following SQL Server  pivot, and it gives me desire result. I want to add total column at end of pivot, where I am finding it difficult.

Please find the SQL I'm using for pivot,

DECLARE @columns NVARCHAR(MAX)
DECLARE @sql NVARCHAR(MAX);
SET @columns = N'';
SELECT   @columns =  @columns+N', p.' +QUOTENAME(Name)
  FROM (
		SELECT distinct Name  FROM #Temp2

   ) AS x;
SET @sql = N'
SELECT 
        P.PNAME,
	
SUM(' + @columns + ') AS TOTAL,  -- here am getting error like incorrect syntaxt near ','
 ' + STUFF(@columns, 1, 2, '') + '
FROM
(
             SELECT P.ProductCode,	
				
				
	 CONVERT(VARCHAR,YEAR(PT.BILLDATE))+''_''+DATENAME(MM,PT.BILLDATE) AS MonthNames  
              FROM TEST PT (NOLOCK)
                    INNER JOIN  Products P (NOLOCK) ON PT.PNAME=P.PNAME

  
) AS j
PIVOT
(
  SUM(SaleQuantity) FOR MonthNames IN ('
  + STUFF(REPLACE(@columns, ', p.[', ',['), 1, 1, '')
  + ')
) AS p;';

PRINT @sql;
EXEC sp_executesql @sql;

DROP TABLE #Temp2


thanks in advance