During the checkout sign-up process, customers are required to enter their full name and email address.
You can add up to three basic text fields to collect additional information from customers.
You might want to know how they heard of you, what they're most excited to watch, etc. These text fields are a great way for you to learn about your audience through strategic questions that can help you understand what encouraged them to sign up.
Create your custom User Fields
Navigate to Settings > User Fields.
Add up to three custom text fields to appear on the signup page, and then Save your changes.
See how they look at the Checkout
Your created User Fields will be placed under the default Name and Email fields.
NOTE: Custom user fields cannot be mandatory. All custom user fields are optional to be filled out.