I read about this convenient fast transport from the airport in Rick Steves " Best of Spain" Third Edition, Revised November 2021, (the most current one available). It says that you can buy the 6 Euro ticket from the driver. A website is given: www.aerobusbcn.com, but when I try to go to this , it takes me to something that does not look like anything like the proper site , and wants a log in. It doesn't look at all right. I then Google searched and went to www.barcelona-aerobus-tickets.com. I shows pictures of the buses and the routes and stops. It then suggests you but on-line to avoid lines for 5.90 Euro. Reading further on the site it says:
Tickets are now sold only digitally, i.e. , you have to but them on-line and they send the ticket to your phone.
Does anyone have recent experience with Aerobus? You can't buy it at the airport when you get there or from the driver, as it says
in "Best of Spain" ?