You can subscribe for a fact sheet in the subscription section.
You enter your e-mail, select whether you want to actively participate in the content creation of the fact sheet by choosing the subscription role Responsible or Accountable or whether you just want to stay informed about the fact sheet by choosing the subscription role Observer. Furthermore it is possible that you can or must choose a specific subscription role like for example Application Owner. This depends on the settings.
You can filter for the Fact Sheets you are subscribed to in the Inventory:
You can follow the Fact Sheets you are subscribed to in the News section under "News for me" and you can even "Subscribe to feed":
You can also filter for the fact sheets you are subscribed to in the Reporting section: