It's okay, Stripe and Shopify Payment Gateway are with us! They are our secure payment processing partner.
Stripe is a secure payment processing partner. They are both a well-established and widely-used online payment service. You can find more information about their business on https://stripe.com/
While charges should show up on your bank statement as coming from "Flexia"™ occasionally "Stripe" might be listed temporarily while the charge is pending, especially on statements from American Express.