If I write a piano piece with chords (and a base) can Dorico write out the figured base for me?
Something like Lesson 6: What is Figured Bass? - YouTube : )
As far as I know, you can enter the bass line, and in the figured bass popover you can write the name of the chord (A7, Dm…) and Dorico will write the correct figures. But no automatic filling of FB according to the notes already written. At least not yet.
You want some free software (Dorico SE) that will guarantee you get 100% marks on the tests in your harmony course, no? 
Now that the cat is out of the bag! 
I am more of a hobbyist for music, and I am studying something wildly different. But it would be fun for me to get quickly see what my “improv” looks like on FB.
Thank you, I see. It would be useful for me, but I guess it is not really requested.
Dorico will give you the note names of the chord that the figures imply, in the bottom ‘status bar’ . I’d say that’s as good as you’re going to get!
I see, then I rather just printout / write them out myself.
But good to know that there is no way to do it automatically. : )
One day somebody will do it (whether in Dorico or not) and I guess it will have the same sort of consequences for teaching harmony as using calculators that can “do algebra and calculus” has on mathematics teaching.
Of course the real learning objective of working out figured bass is not “write the correct figures on the work sheet” but “understand the process for finding the correct figures, so you can do it on your own without any help”.
to be fair to calculators - garbage in, garbage out - one must understand the underlying mathematics to get cogent results. the same can be said for ‘auto-harmony’ - gibberish in, gibberish out. of course with harmony you can hear the gibberish - but can you fix it?