  Neutral triple gauge couplings (nTGCs) are absent in the Standard Model (SM)
and at the dimension-6 level in the Standard Model Effective Field Theory
(SMEFT), arising first from dimension-8 operators. As such, they provide a
unique window for probing new physics beyond the SM. These dimension-8
operators can be mapped to nTGC form factors whose structure is consistent with
the spontaneously-broken electroweak gauge symmetry of the SM. In this work, we
study the probes of nTGCs in the reaction $e^+e^-\to Z\gamma$ with
$Z\to\ell^+\ell^-\,(\ell =e,\mu)$ at an $e^+e^-$ collider. We perform a
detector-level simulation and analysis of this reaction at the Circular
Electron Positron Collider (CEPC) with collision energy $\sqrt{s} = 240$ GeV
and an integrated luminosity of 20 ab$^{-1}$. We present the sensitivity limits
on probing the new physics scales of dimension-8 nTGC operators via
measurements of the corresponding nTGC form factors.
