  The azimuthal variation of jet yields in heavy-ion collisions provides
information about the path-length dependence of the energy loss experienced by
partons passing through the hot, dense nuclear matter known as the quark-gluon
plasma. This paper presents the azimuthal anisotropy coefficients $v_2$, $v_3$,
and $v_4$ measured for jets in Pb+Pb collisions at $\sqrt{s_{NN}} =$ 5.02 TeV
using the ATLAS detector at the LHC. The measurement uses data collected in
2015 and 2018, corresponding to an integrated luminosity of 2.2 nb$^{-1}$. The
$v_n$ values are measured as a function of the transverse momentum of the jets
between 71 GeV and 398 GeV and the event centrality. A nonzero value of $v_2$
is observed in all but the most central collisions. The value of $v_2$ is
largest for jets with lower transverse momentum, with values up to 0.05 in
mid-central collisions. A smaller, nonzero value of $v_3$ of approximately 0.01
is measured with no significant dependence on jet $p_T$ or centrality,
suggesting that fluctuations in the initial state play a small but distinct
role in jet energy loss. No significant deviation of $v_4$ from zero is
observed in the measured kinematic region.
