I've been trying to subscribe from the App, but the destination always error out. If the devs would place an easy to find link on the website, I'm sure there would be a lot of people subscribing, besides myself.
Hey thank you for writing to us, for now there's a difference between logins on the website and the ones on the app so this makes it difficult (but we will look into it) to add subscription through the website. As for subscribing through the app, looks to be working find, if you're experiencing issues with it please contact our support: https://support.curseforge.com/en/support/tickets/new