If you need to create user accounts for e.g. VIP or testing you can do so through the console. Go to the user section in the console and click on "list users". The create user button is in the upper right corner.
1. Step: User settings
Add the name, email, password, locale (language) and country.
2. Step: User details
You can activate the parental control on the account and You can add user tags in this step so that you can find your e.g. VIP customers more easily again later. Also, remember that you are not allowed to add the users to your email newsletter without asking for the user's consent.
Step 3: Preview and create
Check that the account settings are correct and then click the save button.
When you have created the account you can either ask the user to purchase an offer or add an entitlement manually to the account. Read more here.