Get Signin Host

{  "rp_id": "string",  "configured_rp_id": "string",  "default_rp_id": "string",  "is_default": true,  "ceremony_origins": [    "string"  ],  "choices": [    {      "rp_id": "string",      "kind": "default",      "covers": [        "string"      ],      "is_current": true    }  ],  "active_passkeys": 0,  "registrable_domains": [    "string"  ],  "spans_multiple_registrable_domains": true}