Not every framework in Prove → Compliance → Frameworks is available on every plan. Ones outside your current subscription show Request Access instead of Enable:
Clicking it explains why directly: "Your subscription does not include this framework. Please contact our support below to enable this framework." — and opens the chat widget so you can talk to the team about adding it.
This isn't a self-serve toggle like enabling a framework already on your plan — it routes straight to a sales/support conversation, since adding a new framework usually means a plan or pricing change. If you're evaluating whether you need a framework before committing, that chat conversation is the right place to ask.