They want you to upload each genome with a new e-mail. They are sending activation code to your e-mail, and you can't use exactly the same e-mail twice. Without activation code you can't see your Ancestry Report.

However, in fact creating a new e-mail for each genome won't be necessary.

You can upload multiple genomes to one e-mail address using such a trick.

Here is how it works:

myoldemail@gmail.com = 1st genome

myoldemail+1@gmail.com = 2nd genome (and you get the activation code to myoldemail@gmail.com)

myoldemail+2@gmail.com = 3rd genome

myoldemail+3@gmail.com = 4th genome

(...)

myoldemail+25@gmail.com = 26th genome

And so on. I used this trick when uploading a dozen or so ancient samples.