CB Redirect Bot not working

I must be missing something obvious here or I don't understand the purpose of this plugin. There's no doc/guide for it.

I want 404 not found error pages to redirect to a single page.

I tried Regex replace like this:

index.php/about-site/.* replace with index.php/about-site

also tried this:

%/index.php/about-site/.*% replace with /index.php/about-site ,
or just "about-site/%" to "about-site.

but it just ignores me.

CB Redirect Bot extends Joomlas core redirect component. Ensure "System - Redirect" is also published, but I recommend setting "Collect URLs" to "Disabled" so it doesn't collect a bunch of URLs (unless you want that behavior). The below for example works fine in my tests.

From: %/testing%i
To: /index.php
REGEXP: Checked

If you try to navigate to /testing then the above will send you to your homepage.