Hi @NgocHoangNguyen,
To create a custom cluster you need to define each of the ZCL structures. These structures contain endpoint definitions, cluster definitions, attribute definitions, addresses, attribute reporting configuration, response configurations and cluster instance data, as well as other configurations.
Yes, you can either utilize a custom cluster or select one from the ZigBee Cluster Library.
For the custom cluster, ZCL structures need to be defined with definitions as endpoint, cluster, attribute, addresses, attribute reporting, response configuration, among other configurations. You can look into more information about the ZCL structures in chapter 6 (ZCL Structures) of the ZigBee Cluster Library.
For reference, you can check the ZigBee 3.0: Adding Clusters, as it describes how to add additional clusters to the Router application.
Best regards, Julián