A URL is not found in the local allow list, block list, or local cache...

During web filtering, the SRX first checks local policy elements such as allow lists, block lists, and cached URL categorization information. If the URL is not available locally, the device sends the URL information to the cloud-based web filtering service for categorization. Juniper documentation for enhanced and cloud-based web filtering explains that when the URL is not present in the filtering cache, the device sends a categorization request to the cloud service. NextGen Web Filtering similarly uses the Juniper NGWF cloud to categorize the URL and provide reputation information. Therefore, the correct action is to forward the URL to the NextGen Web Filtering application in the Juniper cloud. It is not simply allowed, blocked, or reset by default before categorization is attempted.