How to send pull request to someone I only have his email

Hello everyone,

As part of a job interview I was asked to write some code and send the result as a pull request.

I opened a new repository for my project, and now that I’m done, I wanted to send a pull request to review my code and commits.

The problem is - I didn’t receive any branch/repository/instruction on how to send him this pull request. 

What should I do now? Do I branch my own code and add him as contributer?

How can I send him my current repository (with all the commits and notes) as a pull request when all I have is his email.

What am I missing?

Thank you very much!