Hmm, I don’t see any on that page.   Here’s an example:
assistant
There is a Subscribe button, but it’s only displayed on pages that have at least one subscriber.  Many pages don’t have subscribers yet, so it’s often a good idea to just tell your friends directly.
assistant
How do you subscribe to a Facebook page?
user
A very popular way to do this is to send a message to a friend or family member on Facebook with the text “+1 subscribe to my page”.  They can then either send the same message, or respond by copying and pasting the URL for the page into the message.  Then your friend will receive a notification that you have subscribed to the page, and they’ll be able to see when you post new content.  Is there any other way to subscribe?
assistant
Is there supposed to be a Subscribe button on the Facebook page?
user