If you’re logged in on the website, those links should “just work” and the subscribe button is in the sidebar. Mobile website also works really well although you have to expand the sidebar to see the button.
If you’re using one of the many different mobile apps you’ll have to let us know which one because they all seem to work completely differently at the moment!
Edit: Just realised you’re on Kbin and it looks like Kbin is stripping the link formatting out of the post for some weird reason, that’s why you can’t click them 🤦♀️