AWS WAF ALB Blocking towards a specific path

I'm trying to mitigate the costs of all the WAF requests evaluations to only one path on my domain, but I do not see the options nor understand the billing for the WAF requests. Can someone give me a better understand if it's possible to only have WAF work towards on path instead of the entire load balancer?

Or what is the best practices to get one path from the current load balancer to be evaluated for Bot traffic?

Thanks