Beacon chain support
Since The Merge, running a consensus layer node (CL) is required alongside the execution layer node (EL).
For merged chains, Otterscan can optionally display CL information. Most known merged chains are Ethereum and Gnosis (mainnet and testnets).
First you'll need to make sure your CL node is fully synced and then enable its REST API support.
You can then enable it in Otterscan.