Where do you define the HMS instance to register the iceberg and delta table?

[alberttwong]

in https://xtable.apache.org/docs/hms, it says

CREATE SCHEMA iceberg_db;

CALL hive_prod.system.register_table(
   table => 'hive_prod.iceberg_db.<table_name>',
   metadata_file => '/path/to/synced/iceberg/table/metadata/<VERSION>.metadata.json'
);

I couldn't find it in the docs where you define the HMS instance? Same question for delta. I can understand Hudi because you're executing the registration command with a HMS parameter.