Micromagnetics is a continuum theory; you start from a discrete Heisenberg model and take the continuum limit of this. Antiferromagnetism inherently breaks the continuum assumption (i.e. that spins vary only slowly) and so micromagnetic simulations are not appropriate for this type of study.

In the past people have used OOMMF/MuMax to look at antiskyrmions, but it is ill-advised. While some energy terms in the Heisenberg Hamiltonian have the same mathematical form as the micromagnetic equivalent and can therefore be mapped to the discrete equivalent simply by multiplying by appropriate constants, this is not true in all cases.

There are a few publicly available tools that can do Heisenberg model simulations and they all have a somewhat different focus.

Vampire - https://vampire.york.ac.uk/

Spirit - https://iffwiki.fz-juelich.de/index.php/Spirit

Fidimag - https://github.com/computationalmodelling/fidimag

Hi Indra Purnama I recommend this reference: Article Theory of skyrmions in bilayer systems

"Skyrmion is an emergent particle consisting of many spins in magnets, and has many nontrivial features such as (i) nano-scale size, (ii) topological stability, (iii) gyrodynamics, and (iv) highly efficient spin transfer torque, which make skyrmions the promising candidate for the magnetic devices. Earlier works were focusing on the bulk or thin film of Dzyaloshinskii-Moriya (DM) magnets, while recent advances are focusing on the skyrmions induced by the interfaces. Therefore, the superstructures naturally leads to the interacting skyrmions on different interfaces, which has unique dynamics compared with those on the same interface."

In this article the researchers theoretically study two skyrmions on bilayer systems employing micromagnetic simulations as well as the analysis based on Thiele equation, revealing the reaction between them such as the collision and bound state formation. The dynamics depends sensitively on the sign of DM interactions, i.e., helicities, and skyrmion numbers of two skyrmions, which can be well described by Thiele equation.

Antiferromagnetic Skyrmions : http://www.issp.u-tokyo.ac.jp/public/npsmp2015/w/w16-3.pdf

There is the program Spirit – Atomistic Spin Code: https://spirit-code.github.io/

SPIN SIMULATION FRAMEWORK: https://github.com/spirit-code/spirit

Click here to see the online operation of it: https://spirit-code.github.io/web.html (The attached images were generated on this website)

This link talk about : Dynamics of antiferromagnetic skyrmion driven by the spin Hall effect

Article Dynamics of antiferromagnetic skyrmion driven by the spin Hall effect

Simulating AFM skyrmion using OOMMF is a very poor approximation. Go for atomistic if you want to AFM skyrmion.