The occ Interface
occ interface allows admins to execute various tasks
from the command line.
Generate a one-time code
Once this app is enabled, it provides a
twofactorauth:admin:generate-code command you can execute with
./occ twofactorauth:admin:generate-code leonida
where "leonida" is the user ID for which a one-time login could shall be generated.
The command will tell you the newly generated code as well as its expiry date. You may now transfer this code to the user via a trusted and secure channel.