Inquiry of the usage of metacyc database in humann2/3

Hi, I am the new for the humann2, and I would like to analyse the pathway by utilizing the metacyc database, I would like to know whether I need to download this database by myself or it would be used by default?
by the way, if I would like to use the customized database, which command should I use?

The MetaCyc files HUMAnN 2 and 3 need to operate are bundled with the software. However, with MetaCyc’s new service model, I think you need an account with them to be able to look up pathways on their website and/or download additional data files.

I’m not sure what you mean by customized database? There are instructions in the HUMAnN manual for defining and using your own pathway database, though this is not typical.