When you start creating a fresh slave site, this is normal that you don't have the DB info filled as the slave site is not yet created.
If you followed the tutorial video 9, once the slave site is defined, you should have a Joomla installation setup that is started to setup the DB and the "configuration.php" for this slave site.
I suggest that you review the tutorial video 9 and put exactly the parameter provided in the video.
www.jms2win.com/en/tutorial#jms12x-9
Sample values:
* Site ID = slave1
* Domain name = {site_url}/multisites/{site_id}
* Deploy directory = {site_dir}