At the moment, Todoist doesn't support sharing the Pro plan via Apple’s Family Sharing or Google’s Family Library.
Is it possible to pay for all my family members from one account?
Yes, if you sign up for the Business plan you can invite your family members to your Business team. Then, as the admin of the team, you will be billed for all its members.
Is it possible to get a discount for my family members?
We do not currently offer a family discount.