CYou mean challenging people? You can set your Security Level to under attack to challenge everyone under Security -> Settings but it's not recommended as it's poor user experience and would block API users and such. Cloudflare has built in ddos protections and such which work well with very high volume attacks, and for anything less you're better off crafting specific firewall rules to try to challenge those requests. Under Attack is more of a "I need to stop the issue right now and gather info to block more specifically" or "I cannot find a pattern to block more specifically" imo
