Spectra email form with submit button placed laterally to input

Hello,

This post (https://wordpress.org/support/topic/align-2-spectra-form-fields-side-by-side/) covers what I’m asking, but perhaps the contents in the link provided there (https://wpspectra.com/docs/spectra-forms-block/) has changed, because I can’t seem to find the the custom class uag-col-2 that’s mentioned. Is this a pro feature? I only have the free version. I’d just like to place my submit button next to (side by side) my input field.

Thank you!