Just select 
at checkout
Keep it simple with Pay in 4. An $800 purchase could be split into 4 interest-free payments of $200 every 2 weeks.
How Affirm Works
At checkout
When you’re done shopping, select Affirm at checkout.
Choose how to pay
Enter a few pieces of info for a real time decision.
Pay over time
Make 4 payments every 2 weeks at affirm.com or in the Affirm app. You’ll get email and text reminders.