ng2-opd-popup does not recognize bootstrap

I'm working with angular cli v.5 and integrate the ng2-opd-popup library to use modals, my problem is that modal elements do not recognize bootstrap4 stylos I hope someone can support me on how to fix it. greetings and thanks. I leave you the modal code.

 <popup #popup1 (confirmClick)="login()">
  <form >
      <div class="form-group row">
          <label for="inputEmai3" class="col-md-12 control-label">Token</label>
          <div class="col-md-12">
          <input type="text" class="form-control" name="email" 
              [(ngModel)]="email" id="email" placeholder="Ingrese su token">
          </div>
      </div>
  </form>
</popup>