A.
It is not possible to use "Biometric Authentication, Passcode Authentication, etc." when using two devices, such as a computer and a smartphone.
You must set up either "One-time Password Authentication (App)" or "One-time Password Authentication (Email)."
For more information, see section "3: For Those Who Log in with Two or More
Smartphones or PCs" of the Expo ID Registration Manual below.
Expo ID Registration manual: