Channel moderators will never be given access to other users IP addresses, it would cause huge security issues.
IP bans are also highly ineffective as it takes minimal effort to circumvent them through proxies (which is easier than ever with the prevalence of browser extensions that change proxy with a single click), and with the exception of business connections the majority of ISPs worldwide use either dynamic or sticky IP address allocation so an IP ban would impact people other than those harassing your channel.
IP bans have their place (particularly in conjunction with wildcards as needed), but that lies with Twitch, not for channel moderators to use. If the harassment rises to the level of it violating Twitch ToS you can report the user through chat and then ban them, and make use of tools like AutoMod and 3rd party bots to help deal with them.