As of September 14th 2019, a new European Union regulatory requirement comes into effect. This requirement is named Strong Customer Authentication (SCA) and will require two factor authentication by default for online payments made through Stripe payment gateway.
Our dev team is currently working on this and we assure you that Stripe integration in Tickera will become compliant before this regulatory requirement comes into effect.
In the meantime, you can continue using Stripe in Tickera as-is and you will not have any problems. If, however, you're concerned about this and want to enforce SCA compliant Stripe payments for your ticketing store right away, you can run Tickera alongside WooCommerce via Bridge for WooCommerce and use Stripe integration for WooCommerce which you should set up as described in their documentation here.