ag-grid delete row on detail table

Question

I have this model for ag-grid data;

data = {
   username: string,
   details: [
     {
      phoneNumber: string
     }
    ]
}

I want to delete a row on details table. I able to delete row/rows on master table(e.g. delete username) with using splice the data row id. But things get mixed up when the details table. I need a parent row number for the delete details table row. But I can't find any helpers on params.api. How to get parent row id or something like that?

Thanks for the help...