To implement a new payment method available for order creation from the admin panel, the "can_use_internal" flag should be used. This flag indicates whether the payment method can be used in the Magento admin panel. Reference: https://devdocs.magento.com/guides/v2.4/howdoi/checkout/checkout_payment.html

In Magento, third-party modules are located by default in two directories: app/code/ and vendor/. The app/code/ directory is used for custom modules, while the vendor/ directory is used for modules installed via Composer. Reference: https://devdocs.magento.com/guides/v2.4/extension-dev-guide/build/module-file-structure.html

The Frontend attribute model class is responsible for formatting the value of a product attribute before it is displayed in the Adobe Commerce system. This class allows developers to control how the attribute value is presented on the frontend.

Magento's optimized web directory is the `pub` directory, which makes direct access to sensitive areas of your application such as logs and cache harder. Reference: - https://magento.stackexchange.com/questions/95832/magento-2-best-root-directory-for-security-reasons - https://devdocs.magento.com/guides/v2.4/install-gde/prereq/apache-tutorial-file-system.html#apache-mode-split

This is done by using the Storefront API to create the custom role, and then assigning that role to the admin user. Please refer to the Adobe Commerce Developer Professional Study Manual from adobe.com for more information on creating custom roles and assigning them to users.