Hello @JenniferL5024 ,
To add the Archive widget to an Email-level account, you'll need to speak with our general phone support so they can confirm security permissions and charges. Once added, you'll be able to access it in your account, add emails to it, and copy the coding. Otherwise it's available by default with Email Plus accounts.
Make sure to check out some of these articles regarding the Archive:
Adding emails to the archive
Adding the archive to your site
Applying styles to the archive
Changing archived email names that display on your site
... View more