HOW CAN I GET THE FINAL TIME OF THE CALLS?

Ok lets rather do it in Power Query

Add a custom column to total the seconds

Here is the Code :

Time.Hour([Hour]) * 3600
+
Time.Minute([Hour]) * 60
+
[Second]

Then
Add another Custom Column to convert it to Time

and here is the code :

#time(0,0,0) + #duration(0,0,0,[Hour converted to seconds])

Finally Change the type of the column to Time

Third Option would be this DAX

Let me know