> ## Documentation Index
> Fetch the complete documentation index at: https://ext.eplus.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

> Common questions about sandbox cards, automatic filling, privacy, and compatibility

<AccordionGroup>
  <Accordion title="Can these cards be used for real payments?">
    No. Payment Sandbox Helper is intended only for PayPal Sandbox, Stripe test mode, and local development. The values must not be used on production checkout pages or for real purchases.
  </Accordion>

  <Accordion title="Are generated card numbers real?">
    No. Random card numbers are generated locally with a valid Luhn checksum and appropriate network prefix. A valid checksum only makes the number structurally valid; it does not represent a funded account.
  </Accordion>

  <Accordion title="Why is a generated card rejected by the sandbox?">
    A provider may require one of its documented static test cards or a specific account configuration. Select a scenario designed for the current provider rather than assuming every Luhn-valid number will be accepted.
  </Accordion>

  <Accordion title="Why did automatic fill miss some fields?">
    The page may use different selectors, a custom component, or secure cross-origin iframes that content scripts cannot access. Confirm that the hostname is supported, then copy and paste any missing values manually.
  </Accordion>

  <Accordion title="Which sites can the extension access?">
    The current content-script matches cover PayPal, PayPal Sandbox, Stripe, localhost, `127.0.0.1`, and `*.appspot.com`. The manifest does not declare access to every website.
  </Accordion>

  <Accordion title="What do PayPal error triggers do?">
    They supply provider-specific values used to exercise declined or validation-error paths in PayPal Sandbox, such as insufficient funds, expired card, suspected fraud, or CVV failure.
  </Accordion>

  <Accordion title="Where are my settings stored?">
    Country, cardholder name, card backgrounds, and other preferences are saved in browser extension storage on the current browser profile.
  </Accordion>

  <Accordion title="Does the extension collect payment data?">
    The project is a test-data helper and the Firefox manifest declares no required data collection. Do not enter real card data into the extension or use it on production payment pages.
  </Accordion>

  <Accordion title="Does it support Chrome and Firefox?">
    Yes. Chrome uses the Manifest V3 side panel, while Firefox uses its sidebar action. Build commands and installation steps differ slightly by browser.
  </Accordion>

  <Accordion title="How do I report a problem?">
    Open an issue in the [Payment Sandbox Helper repository](https://github.com/ePlus-DEV/payment-sandbox-helper/issues). Include the browser, extension version or commit, provider, test page type, expected behavior, actual behavior, and redacted screenshots. Never publish real card or customer data.
  </Accordion>
</AccordionGroup>