Hello. Like this?
Download the form I created here: export.json - Droplr
Save that to your desktop, then Import the form from your WordPress dashboard Forms → Import/Export → Import Forms page.
Then embed the form in a page on your site and view it.
Each field gets a Custom CSS Class name on the Appearance tab of:
gfield--width-one-sixth
Note the two dashes between gfield and width. It looks like the forum software converted that to a long dash like this – when it was rendered in the other topic.
The other thing you need to do on the Form Settings for the form overall is give it a Custom CSS Class of gf_simple_horizontal to put the submit button inline.
If you have any other questions, please let us know.