OK, you hadn't imported the s-89 then. Which explains it doesn't show up. (If you had imported it and it wouldn't show up, that'd be a different problem...)
The idea is: you take the s-89 as provided by the branch (the pdf !) and put it into the template folder. Not Dropbox. It doesn't do anything there. And also not the default template folder of TB, but the custom one that you defined in Settings (see picture). If you haven't defined such a folder, you should do it. I do not know why it does not work in the default folder. Put the file into that folder when TB is not open.
When now you open TB, it should convert the pdf to jpg and then when you try to print, it will scan the jpg. If both steps work correctly you are good to go. Both procedurs are a one off, so they won't repeat. In my case importing s-89's sometimes does and sometimes doesn't work. If it doesn't work in your case, pls come back here and explain where you got stuck.