How do I restore from an MBOX into a Google Groups (ie, groups.google.com)?

[Sid B]

Might be related to my post - https://groups.google.com/g/got-your-back/c/6YxtSV_033Y/m/FNPFNWyWBQAJ

I am trying to restore from an MBOX into a public Google Groups (which I created using MYGM...@gmail.com, and of which I am an admin).

This command restores the emails in my gmail account itself, whereas I want it to restore it to the googlegroups.com itself.

gyb --email MYNEW...@googlegroups.com --action restore-mbox  --use-admin MYGM...@gmail.com --local-folder d:\ 

d: is a USB drive having one 27 GB .mbox file. Takeout's export.