The Later account is part of our Personal ($3/month) tier. When you sign up or upgrade your account, you will be able to set up the Later account if you are on a tier that offers it.
Prior to May 20, 2020, Acorns offered a separate tier for just Invest and Later, but now is part of our Personal tier with Spend. We are no longer enrolling new users on this tier. If you are on this legacy plan and have questions, please reach out to our customer support team or visit this FAQ.