Use the SFTP Upload File action to upload a single file to the SFTP server.

Source File
Select the file that you want to transfer. This action only supports transferring a single file. To transfer multiple files use either SFTP Upload Files or SFTP Upload FileSet.
Destination File
Specify the destination directory or destination directory including the filename on the SFTP server. You may specify a directory that doesn't exist and it will be created for you. Make sure the directory is a full path (specified from the user's home directory). The SFTP protocol doesn't have the concept of a "current directory" like FTP does. If specifying a filename, then the file will be transferred as the new filename.
Upload Mode
Select what should be done if a file already exists on the server with the same name. Select either: Overwrite, Skip, Append, or Resume.