You can sign up directly on the Publicus website — pick the sign-up link and follow the steps.
Your trial runs for two weeks by default. If you're an enterprise or a larger organisation, get in touch and we'll usually give you at least four weeks.
Sign-up runs through Stripe, so you'll be asked for a card when you start. You won't be charged during the trial, and you can cancel at any point before it ends — message us here in chat and we'll take care of it immediately.