Do I need an account to book?
Yes. An account is what holds your booking reference, your trip status and your payment record, and it is what lets you leave a review afterwards.
You can browse every trip on the site without signing in. An account is only needed at the point you send a request, and it takes an email address and a password.
Once you have one, your trips, their statuses and their payment records sit in a single place, which matters when you are dealing with a booking from another country in a different time zone.