  We compute the exclusive electroproduction, $\gamma^* p \rightarrow V p$, of
heavy quarkonia $V$ to NLO in the collinear factorisation scheme, which has
been formally proven for this process. The inclusion of an off-shell virtuality
$Q^2$ carried by the photon extends the photoproduction phase space of the
exclusive heavy quarkonia observable to electroproduction kinematics. This
process is relevant for diffractive scattering at HERA and the upcoming EIC, as
well as at the proposed LHeC and FCC.
