how i assign id to custom button

jatin gajera

            null,
        ],
      dom:'Bfrtip',
      select:true,
      buttons:[
              'copy','csv','pdf',
              {
                extend:'print',
                text:'print all'
              },
              {
                text:'delete',

              },
              {
                extend:'print',
                text:'print selected',
                exportOptions:{
                  modifier:{
                    selected:true
                  }
                }

              },

        {
          text:'button',
        },
      ],

how i assign id to delete button??