显示/隐藏ngx-daterangepicker-material时清除今天的日期

Question

每当显示/隐藏dateRangepicker时，我都会将该字段重置为null。但是它将自动设置今天的日期。无法使用任何属性.ngx-daterangepicker-material版本2.1.8清除今天的日期

ts

this.showDate = true;
formData.travelStartDate = null;

html

 <div class="col-md-6" *ngIf="showDate">
      <div class="form-group">
        <label class="control-label required">{{ 'TravelDate' | translate }}</label>
        <div class="date-range-picker">
          <input type="text" pInputText ngxDaterangepickerMd  [maxDate]="today"  [showRangeLabelOnInput]="false"
            [locale]="{applyLabel: 'ok', format: pageSettings.defaultDateFormat.toUpperCase() }"
            [(ngModel)]="formData.travelStartDate" formControlName="fTravelStartDate" [linkedCalendars]="true"
            [showClearButton]="true" 
            class="form-control date-control-input" [timePicker]="false" [opens]="'left'" [singleDatePicker]="true"
            [autoApply]="true" />
        </div>
      </div>
    </div>