Credential is required in all integrations to easily track a single user's transactions and properly bill you for usage (if not populated, costs may be higher than expected).
This field should be populated with a "friendly" name to unique identify your users. Email or SSO ID are most commonly used for credential.
This data can then, for example, be used to search for "[email protected]" in ID DataWeb's Administration Console to quickly see all of sample's attempts + decisions.
{
"credential": "[email protected]",
"userAttributes": [
...
]
}