Make sure you're using an IP from America when opening the link. If one doesn't work try another server, preferably also from America. I was also able to access the link from a couple of European servers. Chrome seemed to work best.
Edit: You don't need a new account for this.
In the past, I have been able to use this on my current, existing account - it does not stack but it should set the subscription to 180 days, best to do a few days before the code expires.
Edit: This is the 2020 version, I have the 2019 version so it may be different
On a completely different note:
Opened the URL and entered an email without being connected to a VPN, received code almost immediately