  In this work we consider the dilepton production via timelike Compton
scattering (TCS) in electron-proton and proton-proton collisions. In
particular, the differential cross section in terms of the dilepton invariant
mass and rapidity is computed within the $k_T$-factorization approach. Besides,
we utilize distinct unintegrated gluon distributions (UGD) in order to compare
their impact on the differential cross section of TCS in $pp$ ($ep$) collisions
evaluated at the LHC (LHeC), HL-LHC (LHeC), HE-LHC (LHeC) and FCC-hh (eh)
center-of-mass energies.
