Things I have tried
email
support@obsidian.md
I got the reply that Please note that we only respond to inquiries about commercial licenses, your account, payment, and add-on services (Obsidian Sync and Obsidian Publish).
Obsidian Support 2:19 AM (11 hours ago) 

to me

Hi, these can both be done from the account pages on Obsidian.md and the forum. Just a heads up, our forum uses a separate account system than our website (obsidian.md), so you’ll need to change both.
–
Leah Ferguson
support@obsidian.md
What I’m trying to do
So, I am assuming that there is some place on the forum site that will tell me how to change my email address. This is contrary to what has been said in other posts.
If I am asking at the wrong forum since there seem to be two of them, please tell me the URL where I should be going.