While you can watch selected video clips without registering, you will have to sign in to watch live content.
Telemundo Deportes asks users to sign in with their cable provider credentials. There’s a huge selection of supported providers, including some popular over-the-top options like Sling TV, YouTube TV, and DirecTV. However, you can only sign up for these services from within the United States. Even a VPN can’t help with this part since they check to see that your payment method is registered to an American bank account.
Unfortunately, these factors make it all but impossible to register for Telemundo Deportes from outside the US unless you have an American friend willing to share their cable login details. That said, if you’re American and simply want to watch when abroad, that’s no problem whatsoever.