In the If activity
System.IO.File.Exists("C:\Users\Dell\Documents\UiPath\Test\BuildDt.xlsx")
In Then → Use Append activity
In Else → Use Write Range activity

Regards
Gokul
In the If activity
System.IO.File.Exists("C:\Users\Dell\Documents\UiPath\Test\BuildDt.xlsx")
In Then → Use Append activity
In Else → Use Write Range activity

Regards
Gokul