What license would be required for ingesting external logs from various vendors?

 To ingest external logs from various vendors, you need a Cortex XDR Pro per TB license. This license allows you to collect and analyze logs from Palo Alto Networks and third-party sources, such as firewalls, proxies, endpoints, cloud services, and more. You can use the Log Forwarding app to forward logs from the Logging Service to an external syslog receiver. The Cortex XDR Pro per Endpoint license only supports logs from Cortex XDR agents installed on endpoints. The Cortex XDR Vendor Agnostic Pro and Cortex XDR Cloud per Host licenses do not exist. References:

Features by Cortex XDR License Type

Log Forwarding App for Cortex XDR Analytics

SaaS Log Collection