  For many years, CoNb$_2$O$_6$ has served as an exemplar of the
one-dimensional Ising model. However, recent experimental and theoretical
analyses challenge its applicability to this material. Prior to that, a
tailored spin model for 3d$^7$ systems such as Co$^{2+}$, known as the
$JK\Gamma$ model, has emerged, featuring Heisenberg $(J)$, Kitaev $(K)$, and
Gamma $(\Gamma)$ interactions. While these interactions are permitted by the
symmetry of the system, their role in CoNb$_2$O$_6$ remains enigmatic. We
present a microscopic theory based on spin-orbit entangled J$_{\textrm{eff}}$ =
1/2 states, aimed at elucidating the roles of Kitaev and Gamma interactions in
shaping Ising anisotropy. Leveraging strong coupling theory, we identify a
dominant ferromagnetic Kitaev interaction. Furthermore, by comparing dynamical
structure factors obtained via exact diagonalization with those from inelastic
neutron scattering experiments, we find an antiferromagnetic $\Gamma$
interaction, which dictates the Ising axis and explains the mechanism behind
moment pinning. Our theory suggests that CoNb$_2$O$_6$ represents a rare
one-dimensional Kitaev chain with significant ferromagnetic Kitaev and
antiferromagnetic Gamma interactions.
