When the URL begins with “HTTPS,” the site is secure, and you are safe to use a credit card. If the site does not include an “s” in this beginning part of the URL, opt out of the online purchase, and try using a third-party payment system like PayPal instead. These sites act as another barrier between an organization and your credit information. If all else fails, try paying in person.
Please read the originial post here: https://kemwienerwald.org/understand-never-use-your-credit-card-for-payment-online-before-you-regret/