Error: Object doesn't support this property or method

I’m attempting to use the GetCreateDtByName() method. I’ve already set the remote directory with ChangeRemoteDir(), and have confirmed the file exists, but the following call generates an error:

GetFileDateFTP = ftp.GetCreateDtByName(sFileName)

I’m using the ActiveX (Chilkat_9_5_0.Ftp2)

Is that not the correct syntax to obtain the file date/time?