You are put into a big room with lots of people. Do some silly/fun activities like acting out a scene with different emotions/characters. Then a one to one interview if you did well beforehand.
I applied in-person. The process took 1 day. I interviewed at Hamleys (London, England) in Sep 2022
Interview
they divide you in teams. they will give you tasks, like 'sell a toy'. you will be chosen for the next round of interviews according to how well you perform, and act.
Group interview in three stages - selling a toy on the spot for a minute, talking on a random topic for a minute, and making up a short role play with the group involving three random objects assigned to you. Then after that you get shortlisted for a one to one interview that is more normal.