  A search for heavy resonances decaying into a $W$ or $Z$ boson and a Higgs
boson produced in proton$-$proton collisions at the Large Hadron Collider at
$\sqrt{s} = 13$ TeV is presented. The analysis utilizes the dominant $W \to q
\bar{q}^\prime$ or $Z \to q \bar{q}$ and $H \to b \bar{b}$ decays with
substructure techniques applied to large-radius jets. A sample corresponding to
an integrated luminosity of 139 fb$^{-1}$ collected with the ATLAS detector is
analyzed and no significant excess of data is observed over the background
prediction. The results are interpreted in the context of the Heavy Vector
Triplet model with spin-1 $W^\prime$ and $Z^\prime$ bosons. Upper limits on the
cross section are set for resonances with mass between 1.5 and 5.0 TeV, ranging
from 6.8 to 0.53 fb for $W^\prime \to WH$ and from 8.7 to 0.53 fb for $Z^\prime
\to ZH$ at the 95 % confidence level.
