—Refutation of Argumentation Ethics—
Argumentation Ethics is a philosophy by Hans-Hermann Hoppe, the overarching idea is that the Non-Aggression Principle, that is absolute private property rights, is presupposed by the activity of argumentation itself, such that to argue against the NAP is to performatively contradict yourself.

The basis of this claim is that to engage in argumentation with an interlocutor, your debate opponent, or multiple interlocutors, is for you to not be intimidating them with the initiation of force, as you and them reject the initiation of force as the legitimate method of resolving a conflict.

Argumentation as a whole is a peaceful activity, where you and your interlocutors presuppose they have the right to exclusive control of their own bodies respectively and the property needed to engage in argumentation, as they require this control to give counterarguments.

To object to such control, or self-ownership as Hoppe calls it, is to performatively contradict oneself because it is in contradiction with the idea that by engaging in argumentation is to legitimize the activity and thus its peaceful norms as the method for resolving conflict.
This is a performative contradiction, thus to argue against the NAP is inconsistent.
 

—Why Hoppe argues Rejecting the NAP outside of Argumentation is invalid—
To reject argumentation or claim argumentation or its norms is an invalid way of resolving a specific conflict, and instead claim such conflict must be resolved via the initiation of force, is to prevent oneself from consistently arguing for the claim. To argue for the claim appeals to argumentation as the way to resolve the conflict, yet the claim contradicts that directly.

Imagine you were to argue that the norms of argumentation are only a valid way to solve the conflict at hand, for the next 30 minutes, and then afterwards the initiation of force would be the legitimate means to resolve the conflict.

To argue this, according to Hoppe, would be to essentially argue that your own argument is invalidated after 30 minutes, because afterwards you would discard the idea that argumentation is a legitimate way to resolve the conflict, thus forfeiting your own argumentative force.
If your own argument is invalidated though, that means its outcome would be left undefended.
 

—The Problem of Argument vs. Arguer—
The first gigantic problem with Argumentation Ethics, is that it does not and can not disprove any arguments themselves, all it attempts to do is prove the arguer, the person communicating their argument, is performatively contradicting themselves.

If the argument being communicated itself stands up to scrutiny, or if it's simply a conclusion derived from premises that both the arguer and their interlocutors do actually accept, then their argument is valid whether the arguer is performatively contradicting themselves or not.
To say the arguer is contradicting themselves becomes reduced to simply meaning they are arguing for a claim that they are not abiding by right now by engaging in argumentation, this is a descriptive fact and has no bearing on the truth of the actual argument being provided.

If it is possible for there to be some arguments that are valid, and true, but not consistently able to be argued for without violating these norms, then Argumentation Ethics fails to protect the NAP.
Imagine someone communicating a proof that 1+1=2 while assaulting you. Does this disprove their proof? No. What if they try to derive a claim by showing it logically follows from true premises? Does them aggressing upon you disprove the deduction? Does it prove the premises false, even if the premises have nothing to do with the norms of argumentation? Again the answer is a firm no.
 

—The Problem of Intellectual Conflict vs. Physical Conflict—
The second gigantic problem with Argumentation Ethics, is that it doesn't actually universalize at all, because there is a difference between accepting argumentation as the (or a) legitimate way to resolve an intellectual conflict, a conflict of ideas and of what claims follow from premises, and accepting argumentation as the only legitimate way of resolving a physical conflict, that is a conflict involving property, physical objects, the "contradictory use of scarce means".

The existence of this distinction allows someone, as many already do, to argue that the Non-Aggression Principle is a valid method of interaction within the context of argumentation, and that the norms of argumentation including the NAP is a legitimate method of resolving intellectual conflicts; while also accepting that to resolve the actual physical conflicts, initiation of force is sometimes necessary if the transgressor fails to concede the intellectual conflict.

To put it more simply, peaceful conduct is a legitimate way to resolve disputes involving the truth value of claims, while the initiation of force can sometimes be a legitimate way to resolve physical conflicts over resources, even if the use of force doesn't actually prove the legitimacy.
Force is instead the tool to enforce claims that are proven peacefully.
The Hoppean rebuttal to this is to collapse the distinction, which can't be justified.