Which app, and what you sign in with
Every app has its own sign-in, because the people using them hold different things.
Steps
A shop or a hub: the email and password you signed up with. On a phone or browser new to it, also a code sent to its number, once.
A fleet: your own phone number and PIN — with your company code, or without it.
A driver: the phone number you signed up with — or, if a fleet took you on, the one it registered — and your PIN.
A store: the email and password you created the store with. On a phone or browser new to it, also a code sent to its number, once.
Sending or collecting a parcel: your phone number and a PIN you choose.
A business — a shipper, importer, expeditor, clearing agent or yard: the Business app, with your own phone number and PIN.
Signing up on the front page, a bar pinned at the top says what you are signing up as, which step you are on of how many, and the next step by name. Tap the bar to see every step. The first step says what to have ready. In the bar at the bottom of the screen, Back returns to the step before, and Help opens the help about joining.