Default domain

I have installed your plugin and it seems to be working as advertised. I have a question though. I have the following:

http://www.domainA.com –> https://domainB.com
http://domainA.com –> https://domainB.com
https://www.domainA.com –> https://domainB.com
https://domainA.com –> https://domainB.com

No matter which version of domainA.com the user puts in, it always sends them to https://www.domainA.com

How can I set it so it directs them to https://domainA.com