SQL Server : Sum multiples series

Hi everyone ! I need some help to build a query.

I have the following query which returns average values with multiples series :

SELECT
  $__timeGroup(DateUTC,'1d', NULL) as time,
  Description as metric,
  AVG(VMActive) as value
FROM "T_ACTIF"
WHERE $__timeFilter(DateUTC)
GROUP BY $__timeGroup(DateUTC,'1d', NULL),Description

Sample of data :

|time|metric|value|
|1585872000|Serie1|13|
|1585872000|Serie2|25|
|1585872000|Serie3|10|
|1585872000|Serie4|23|
[…]

Instead of returning multiples series, I’d like to sum them (without using stack) into one value like this :

|time|metric|value|
|1585872000|Total|71|
[…]

Can you help me to achieve this ?

Try thi: