Eventsforce provides an "Admin registration" option allowing you to complete the registration on behalf of an attendee. Completing an admin registration allows you to register an attendee without knowing their password.
When creating test registrations, Eventsforce recommends against using backend user email addresses (the email address used to login to Eventsforce). Using these email addresses for tests could result in the Eventsforce user getting locked out of the system, experience erroneous results, or seeing incorrect data associated with their profile. For testing purposes, Eventsforce recommends using an alternative or fake email.
Completing an admin registration
Go to the event in which you want to register the attendee
Click the "+" icon in the top left and select "Registration"
Proceed through the registration as normal
(Optional) Select to send a new registration email to the "Attendee" prior to completing the registration (see below)
Tips
You will not be asked for a password even if the person being registered already exists in Eventsforce
You will not see some design options such as the "event logo" to simplify the process
You may see additional "admin portal only" questions which an attendee would not see
You will see additional payment options such as "Freebie" and "Admin price override"
By default, no confirmation email is sent to the attendee