I have used Variable type - Array of string and Expression - Directory.GetFiles(“E:\GoogleSheet\GoogleSheet”)
But still showing this error
Main.xaml: Compiler error(s) encountered processing expression “Directory.GetFiles(“E:\GoogleSheet\GoogleSheet”)”. ‘Directory’ is ambiguous, imported from the namespaces or types ‘Microsoft.Graph, System.IO’.
It seems that there are two namespaces which has the same Method Directory, for your case, you may need to include the System.IO along with the Directory.GetFiles like below :