  At the LHC, the gluon-initiated processes are considered to be the primary
source of di-Higgs production. However, in the presence of a new resonance, the
light-quark initiated processes can also contribute significantly. In this
paper, we look at the di-Higgs production mediated by a new singlet scalar. The
singlet is produced in both quark-antiquark and gluon fusion processes through
loops involving a scalar leptoquark and right-handed neutrinos. With benchmark
parameters inspired from the recent resonant di-Higgs searches by the ATLAS
collaboration, we examine the prospects of such a resonance in the TeV-range at
the High-Luminosity LHC (HL-LHC) in the $b\bar{b} \tau^{+}\tau^{-}$ mode with a
multivariate analysis. We obtain the $5\sigma$ and $2\sigma$ contours and find
that a significant part of the parameter space is within the reach of the
HL-LHC.
