# How to label with numbers atoms when MoleculePlot3D

I want to place a number on each atom (on a sphere) upon 3D plotting a molecule. For example, from:

mol = Molecule["h2co"]; MoleculePlot3D[m, {1, 2, 3, 4}, PlotLegends -> {"1", "2", "3", "4"}]

I get this:

But, this is not what I want. Instead of having this legend, I would like to have labels on the atoms themselves, like this:

.

Any ideas on how to do this?

 mol = Molecule["Formaldehyde"];