The free trial starts when you sign up and usually lasts 30 days. Everything works during the trial, for every role, with the driver app and the customer portal. No card is needed to sign up, to set up or to book.
An Admin or Accounts / Payroll can pay on the Billing page at any time during the trial: the paid months start when the trial ends, so no free days are lost. The top bar shows the days left ("Free trial · 27 days left"). In the last 5 days you get reminders, and if the trial ends without a payment FleetKraft stops (read-only) until an Admin pays.