  In the preprint arXiv:2110.08210, some comments on our paper recently
published in JHEP \textbf{09} (2021) 053 have been made. Since some of the
comments are completely wrong and others are quite misleading, we decide to
clarify the relevant issues in a formal reply. First of all, nothing is wrong
about our calculations and physical results in the original paper. Second,
there is no logical gap to fill at all. The fact that the $N$-dimensional
unitary group over the field of complex numbers ${\rm U}(N,\mathbb{C})$ is not
a linear algebraic group is actually irrelevant for the validity of the
Molien-Weyl formula. As we shall explain in this reply, all the comments in
arXiv:2110.08210 arise from the misunderstanding and misinterpretation of our
discussions and results.
