How many amperes should I select for the DXAdvanced series power supply circuit breaker?

This will be the same as the switch specifications in the operation guide. No /P1 option: Steady-state current rating 1 A or highter, inrush current rating 60 A or higher.
With /P1 option (with 24 VDC/AC power supply): Steady-state current rating 3 A or higher, inrush current rating 70 A or higher.