About Extracting 3D Information from SDF

[Ranceeeee]

Hi OGB-LSC Team,

For PCQM4M-v2, I want to use the provided pcqm4m-v2-train.sdf.However, because I do not know much about chemistry and I am not familiar with RDkit toolkit, I do not know how to get 3D information from SDF. Here are some of my attempts. I'm not sure if I did it right.
I first try GetPropNames() to get the list of the properties of mol.

suppl = Chem.SDMolSupplier('/data/pcqm4m-v2-train.sdf')
    for idx, mol in enumerate(suppl):
        print(f'{idx}-th rdkit mol obj: {mol}')
        print(mol.GetPropNames())

But what I got was {}.
Then I tried mol.GetConformer().GetPositions() and I can get the coordinates, but I'm not sure whether the coordinates are correct, because I don't particularly understand the specific meaning of conformer.

Thanks