Be prepared to secure 3D soon, we have received informations already from Stripe, their solution is mostly hosted on ecommerce websites :
On 14 September 2019, a new European regulatory requirement called Strong Customer Authentication (SCA) will introduce two-factor authentication requirements for many online payments in Europe. Payments that aren’t authenticated will be declined by your customers’ banks.
We’ve released a new payments API and SCA-ready products to help you prepare for this change. To get ready for these new rules and avoid having many European payments declined, you’ll need to make changes to your payment flows and Stripe integration by 14 September 2019. Read our docs to learn more about SCA and the required changes.
For Paypal, the solution is not hosted in 90% of cases on the e-commerce site (redirection to paypal website for payment), no need for any changes in this case, Paypal is already managing the relationship of secure 3d verification if the bank requests it ...