Hi.
This functionality doesn’t currently exist. I believe you’re requesting the same thing as one of our existing feature requests: https://tribe.uservoice.com/forums/195723-feature-ideas/suggestions/11641629-allow-manual-entry-of-attendee-information
Please do add your vote there.
This allows us to gauge interest in this particular feature request, which helps us prioritize our development efforts.
You could try the User Switching plugin (third-party, not guaranteed or supported by us) to submit it yourself while logged into their account. This could also be a great way to go if you’re wanting them to receive the same email confirmation they would have received had they purchased themselves.
Please let me know if you have any follow-up questions on this topic.