Elias here with Shopify Support. Thank you for this inquiry.
If you need to restrict certain customers from accessing your website and products, you can use Fraud Filter app to help protect your business. Fraud Filter allows you to set up rules that can block certain customers or restrict the checkout for certain customers. The filtering can help reduce chargebacks and block potentially-fraudulent orders. We have a guide to help with setting up your Fraud Filter.
Are you using Shopify Payments? If so, Shopify Payments helps protect against fraudulent orders and chargebacks with a feature called Fraud Protect. If you’re using Shopify Payments in the US, you can check your eligibility and set up Fraud Protect. We also have a guide to help with fulfilling orders with Fraud Protect. If you are not located in the US or are ineligible to use Fraud Protect, you can use a similar third-party service called Signifyd. If you require assistance with Signifyd, you can always reach out to the developer directly through the contact information found in the Support section of the app’s page.
If you are looking to protect your account itself, I recommend setting up two-step authentication. Two-step authentication makes it more difficult for an unauthorized person to access your account. There are several ways to retrieve your authentication codes:
Let me know if these options help! If you have any further questions regarding this topic, feel free to reply to this thread and I’d be happy to help.