  High-mass star formation theories make distinct predictions on the properties
of the prestellar seeds of high-mass stars. Observations of the early stages of
high-mass star formation can provide crucial constraints, but they are
challenging and scarce. We investigate the properties of the prestellar core
population embedded in the high-mass clump AGAL014.492-00.139, and we study the
kinematics at the clump and the clump-to-core scales. We have analysed an
extensive dataset acquired with the ALMA interferometer. Applying a dendrogram
analysis to the Band o-$\rm H_2D^+$ data, we identified 22 cores. We have
fitted their average spectra in local-thermodinamic-equilibrium conditions, and
we analysed their continuum emission at $0.8 \, \rm mm$. The cores have
transonic to mildly supersonic turbulence levels and appear mostly low-mass,
with $M_\mathrm{core}< 30 \, \rm M_\odot$. Furthermore, we have analysed Band 3
observations of the $\rm N_2H^+$ (1-0) transition, which traces the large scale
gas kinematics. Using a friend-of-friend algorithm, we identify four main
velocity coherent structures, all of which are associated with prestellar and
protostellar cores. One of them presents a filament-like structure, and our
observations could be consistent with mass accretion towards one of the
protostars. In this case, we estimate a mass accretion rate of $
\dot{M}_\mathrm{acc}\approx 2 \times 10^{-4} \rm \, M_\odot \, yr^{-1}$. Our
results support a clump-fed accretion scenario in the targeted source. The
cores in prestellar stage are essentially low-mass, and they appear subvirial
and gravitationally bound, unless further support is available for instance due
to magnetic fields.
