I transfer from operation team to sales team. My line manager interviewed me for the first round, then the head of sales interviewed me for the second round. Mostly behavioral questions, plus your understanding of the job role, plus their introduction of the job role and career trajectory. If you don't know about our service, do your homework and make sure you know how we serve our client and where we can add value. Aline yourself with the required quality of an account manager and show that you are coachable. Dont forget to be confident and relaxed. My manager and our head of sales are nice and smart peeps, impress them but be yourself.