Can I use this to redirect from a .html to WP page?

I’ve installed the Redirection Plugin and activated it but I can’t get it to redirect.

On the redirect page within the plugin I put the source url as:

https://www.domainname.com/html/aboutus.html

but the plugin strips that back to /html/aboutus.html

I put the target url as:

https://www.domainname.com/aboutus/

Match was set to url
Action was set to Redirect to url
Regular expression was left unticked

But when I enter https://www.domainname.com/html/aboutus.html into a browser it still goes to the old html file ratherthan the new WP page.

What have I done wrong? Or does this plugin only work with WP pages and posts?

(The reason I’m trying to do permanent redirects is that an old hardcoded website has been replace with a WP website – with no change to the domain)

Thanks

https://www.ads-software.com/plugins/redirection/