The SMTP details are your normal email details. If you log in to view your emails elsewhere (for example, on your phone, or a web client), it’s the same details. The server/host needs to be set to your email provider, but this does vary from provider to provider.
The email address that was set up when I checked in my previous post, was set to a Hotmail email address but trying to use Gmail for SMTP, which Gmail will reject.
The Hotmail details above were found by doing a quick search online. What domain are you using (this is the part after the @ symbol)?
The code is necessary for verification. We do this to ensure it’s working. If you don’t/can’t receive the code, then the set up itself doesn’t work.