The following links in 5.3 Configure Nodes and Entitlements returns 404 error for 2.2 version.

2. Register your nodes with Red Hat using the Red Hat Subscription Manager (RHSM)
3. Attach your nodes to your 3scale subscription using RHSM.

and for:

4.3. Configure Nodes and Entitlements returns 404 for 2.1 version:

2. Register your nodes with Red Hat using the Red Hat Subscription Manager (RHSM)
3. Attach your nodes to your 3scale subscription using RHSM.