How to associate WAF Route-Path policy to azure application gateway


I am looking for example code to associate WAF route-path based policy with application gateway.
Currently I do find the supported arguments in

path_based_rule_ids- (Optional) A list of URL Path Map Path Rule IDs from an azurerm_application_gateway

However this is not associating the policy with application gateway.
I am not sure why this argument is used for.

Do you have any examples to associate the WAF policies with appgateway ?

Thank you.