autocomplete drop down is not appear

[dineshmaths1]

public requestAutocompleteItems = (text: string): Observable<Object[]> => {
    this.members_response=[];
    let p = {
      firstName: text,
      lastName: text,
      email: text
    };
     return this._searchService.application(p).map(
      data => {
        let r=[];
        this.members_response=[];
        if (!_.isEmpty(this._global.getVal(data, 'response.docs', ''))) {
          let result = this._global.getVal(data, 'response.docs', '');
          for (let s in result) {
           r.push({ email: result[s]["email"], id: result[s]["id"] });
            //this.members_response.push({ email: result[s]["email"], id: result[s]["id"] });
          }

        }
        console.log(r,JSON.stringify(r),text);
       return r;
      });
  };

<tag-input  (onAdd)="memberInvitieesCount($event)"
              (onRemove)="memberInvitieesCount($event)"   [placeholder]="''" [secondaryPlaceholder]="''" formControlName="invitees" theme='bootstrap'  [(ngModel)]="invitees">
                <tag-input-dropdown  [showDropdownIfEmpty]="true"
         [displayBy]="'email'"   [identifyBy]="'id'" 
         [autocompleteObservable]="requestAutocompleteItems" >
         <ng-template let-item="item" let-index="index">
           {{item|json}}
          ({{ index }}) {{ item.email }}
      </ng-template> 

this my code I have one data Array [ {…} ] [{"email":"xxxxx@GMAIL.COM","id":"b2dacdd9-7953-31b3-9c46-dda8300b6a42"}] But its not displaying on dropdown