Stripe has recently added SCA (Strong Customer Authentication) to improve security of payment transactions. PSD2 regulation will require Strong Customer Authentication (SCA) for online payments.
If your site is having Stripe payment gateway then it is mandatory to update it to the latest version with SCA.
After September 14, 2019, PSD2 regulation will require Strong Customer Authentication (SCA) for many online payments made by European customers to enhance security and avoid fraudsters.
Strong Customer Authentication will apply to “customer-initiated” online payments within Europe. As a result, most card payments and all bank transfers will require SCA.