You need a Google Play Books Partner Center account for Google distribution. But first, you need a Google email to create one.
For this, follow these steps:
1. Open the Create your Google Account page, fill out the form and click on 'Next'.
2. Add your personal information (optional) and click 'Next'.
3. Add your phone number for more Google services (optional). You can choose 'Skip' or the 'Yes, I'm in' button.
4. Add your security settings and click 'Done'.
Now your Google account is ready to use!
The next step is to register a Google Play Books Partner Center account. To do so, go here.