integrate WAF CLOUD with ELB AWS

Hello, I have a very basic question, I currently have applications with several instances that are balanced by an elb of aws, now a waf will be put to protect those instances, since I do not have the ltm module I want the balance to be handled by AWS but it turns out that the ELB is a balancing by request dns and I do not have a virtual ip, so I do not know how to send the analyzed traffic that comes out of the waf to those servers, is there any way of approaching it?