So this is related to a previous law (the CDA? Not sure) that requires special accommodations for users under 13 years of age in order to separate kids and porn (also kids and predators). For most social media platforms the response was to limit the age in the TOS to 13 years.

Did you click a TOS confirmation when you joined facebook? Congrats, you asserted you're at least 13 years old. Were you underage at the time? Congrats! You committed a felony violation of the CFAA (though this was fixed somewhere in the mid 2010s). It was never enforced, but the assumption was if you're tweeting you're old enough to read swearing.

In time we established that kids who want to see porn will gladly pretend to be an old person to do it. If someone admits they're underage, and you're sexually explicit at them, then yes Chris Hanson wants you to have a seat.

(Our rules regarding sex and underage people vary from county to county, and while a teen boy and a teen girl of like ages can get it on without violating the law in every US county, this is not always the case when it comes to two boys or two girls or enbies of any stripe, and very few counties have protections for teens doing anything else, like sexting their sweetheart. So be safe!)

That said, currently all a porn site has to do is put an age-gate where you click to assure you're over 18 and can witness the content of M-rated video games. If Louisana is going to require more (such as mandating a license check) they'll have to specify, and in being specific the law will then interact with commonplace rights to privacy, which includes engaging with the internet while staying anonymous.

So far we don't have a way to prove one's age without also compromising their specific identity, a consequence which has a chilling effect that most would-be moral guardians depend on. Since the porn industry depends on people obtaining porn anonymously, we can expect there will be some very serious first-amendment and fifth-amendment challenges to this law.