GetFiles() is throwing an error when file does not exists

Question

I have a script task in SSIS to get .xlsx file at a specific location and do some operations on the file.

My code:

public void Main()
{
    // TODO: Add your code here
    Microsoft.Office.Interop.Excel.Application excelApp = new Microsoft.Office.Interop.Excel.Application();

    var dir = new System.IO.DirectoryInfo(FILEPATH);
    var fullFilePath = dir.GetFiles("*.xlsx").Select(f => f.FullName).First();
    
    if (fullFilePath != null)
    {
        //FILE OPERATIONS
    }

    Dts.TaskResult = (int)ScriptResults.Success;
}

When I run the code and if no .xlsx file is available at the file location, I am getting an exception. Is there a way to handle this?