A.
A one-time password is a disposable password that is only valid once.
"Authentication by Email" in which a one-time password is sent to you via email, and "Authentication by App" in which a one-time password is sent to you via an authentication app, are available for Expo IDs.
Detailed instructions on how to set up the system can be found in the Expo ID registration manual, which can be found in the "Download Materials" section of the FAQ page, so please check it before registering.
ExpoID registration manual: