Angular - how to add detail in nested object?

My JSON structure looks like this:

{
    "id": 1,
    "name": "Marks, Price and Conn",
    "description": "Newton",
    "installations": [
      {
        "id": "1",
        "name": "ENIM",
        "key": 106789,
      }
    ]
}

And when in my angular page I click on the client I want to add an installation. How to get current client values and then add a new object to subarray?

I tried simple

export class AddInstallationComponent implements OnInit {
  clients: any;
  client = {
    name: '',
    nip: '',
    description: '',

  installation: [{
    name: '',
    key: '',
  }]
 };

  constructor(private clientService: ClientService) { }
  saveInstallation(): void {

    const data = {

      name: this.client.installation['name'],
      key: this.client.installation['key'],

    };

    this.client.installation.push(data)

  }
}

But I don't know how to get values for my current client which I clicked.