TextOutputStream.Append
From Real Software Documentation
Method
Opens the passed file so that text can be appended to existing text.
If no file exists at the specified location, one is created. If the file cannot be created or opened for appending, an IOException is raised. The append is done by calling Write or WriteLine. The Append shared method replaces the deprecated FolderItem.AppendToTextFile.
Example
This example appends the text in TextField1 to the text file that was opened by GetOpenFolderItem:
