Multiple inboxes for newsletters

Is there a way to add multiple inboxes for newsletters?

In my case, I’d like to have one Brew that shows only Substack publications, so I thought I could forward all Substack mails to a specific inbox at Mailbrew, and create a Brew with only those mails.

I’m aware that I could sign up at Substack with my Mailbrew inbox but I don’t want to do that.