A bad example from Tinyrituals
They have Afterpay on the Checkout but promote it neither on product pages nor on the shopping cart. They have not too cheap prices, so for their shoppers, especially for those who buy 2+ products (who are the most valuable customers for the company), it could be a very good incentive to make purchases. Therefore, they still have something to work on in order to increase the conversion rate.
A bad example from Gymshark
They also have Afterpay on the Checkout (and even have an Afterpay icon on the image on Mobile devices) but don't promote it on the shopping cart. So they could improve shopping cart design by adding installment price below the Total (i.e. $24 USD every 2 weeks via Afterpay. Interest-free). It could increase both conversion rate (for those who can't afford to pay $96 right away) and AOV (for those who will buy more items per order due to installment option)
A bad example from Aloyoga:
They have the section with installment price, but it's placed below the "Need help?" section, far from the Checkout button. Users need to scroll to the bottom of the cart to see it. That's an awful implementation of this element. As a result, most users will never see it. There is more to work on for Aloyoga designers and marketers.
A good example from Casper
They are selling costly products and must have and promote installment payments very well. And they do! You can see the line below the Checkout button that shows the price divided by 24 months and "0% APR" which is another essential thing. Also, they have Learn More button, so users could read all the details about how it works.
A good example from Leesa shopping cart.
Right under the Checkout button, you can see a line of text with a logo about installments payment. It shows the price per month and contains the well-known logo of Affirm. Well done!
A good example from Puravida
My subtotal is around $68 and right below the subtotal price, they show me an installment option of just $17/month. It also contains the logo of Afterpay, making it easier for the user to notice and realize the presence of such an option. Another important thing is that they likely use Afterpay as it's the most popular solution in the US, which is another essential factor. Good job!