Which plugin is required for external storage credentials?

The Discovery External Credential Storage plugin is specifically designed to manage and store credentials that are required for accessing external systems and services within the ServiceNow platform. This plugin facilitates secure retrieval and handling of sensitive information such as usernames and passwords, enabling effective communication between ServiceNow and various external entities.

This capability is particularly important for Service Mapping, as it often needs to interact with external sources to gather necessary data. The plugin ensures that credentials are not hardcoded into scripts or directly exposed, thereby maintaining data security and compliance with best practices.

The other plugins listed do not serve the same purpose as the Discovery External Credential Storage plugin. Each of them addresses different aspects of credential management or security but does not specifically focus on the secure management of external storage credentials in the context of Service Mapping. In the context of the question, the Discovery External Credential Storage plugin is indeed the required choice for handling external storage credentials effectively.