Second comment in the thread, since I decided to go hunting for alternatives: https://discuss.privacyguides.net/t/alternatives-to-privacy-com-which-dont-require-a-u-s-phone-number/30692
edit 1: Okay I am trying out Halocard right now. What the actual fuck, it sends the verification code via Whatsapp to the phone number I provide.
edit 2: no wait I received it as a text. It looks like whatsapp has a service to send text to people.