Every time I open my email to get the 6-digit code and open Dwellsy's website, I need to enter my email address again and it generates a different code. How can I get past that?

The easiest way to login to your account is to open your email in a different tab or directly on your email app if you're using a mobile device. That way you can copy the 6 digit code sent to your email, go back to the tab that has Dwellsy website open and paste the code.