How to mail GitHub for a name squatting notice?

How to mail GitHub for a name squatting notice as I saw an account which is publicly inactive and I want that username.
I cannot find out how to contact GitHub mail.
Please help me.

Hey - you can open a ticket to have the account reviewed.

Be aware though, the wait on these tickets is long. You may be waiting more than a month.

Thanks for leaving a note on the wait time. That was helpful.