The most expensive screen in a booking app is the sign-up form. A traveler who wants a ticket for tonight's coach will not make an account first, so TicketBus365 does not ask. A guest can search, compare departures, choose seats and pay with nothing but an email address for the ticket.
Registered users sign in with a one-time code instead of a password: type the email, receive a code, type the code. There is no password to forget, reset or leak, and the same screen serves a first visit and the hundredth. After a guest has booked, the app offers to keep the details, which is when an account is useful: it is where the tickets live.
The design problem is that two kinds of traveler walk the same flow. Their paths join at the passenger step, and everything before it works the same for both. The e-ticket, a QR code and a PDF, is the real reward, so it is the first thing on the confirmation screen, ahead of any invitation to sign up.