I have a container component (called file-container) with an ngbPopover button. The content of the popover is another component. (It is used to select a file for upload).

<button type="button" 
        class="btn btn-secondary popover-btn" 
        placement="top"
        [ngbPopover]="popContent" 
        popoverTitle="Click to add files - will be a label" 
        container="body" 
        trigger="manual"
        #popover="ngbPopover"
        (click)="populateDropdownList()">
  Click to add files
</button>
<template #popContent>
  <app-file-uploader [maxFiles]="maxFiles"
                      [fileNames]="fileNames"
                      (onUpload)="uploadEboxAttachment($event)">
  </app-file-uploader>
</template>

The app-file-uploader emits an event when the Upload button is clicked. The container component handles the actual file upload to the server.
I want the file-container TypeScript code to handle closing the popover too. So that after it recieves a reply from the server, it closes the popover.
How can I pass the popover to the .ts file so that I can call .close() on it?
EDIT- ts code:

createEboxAttachment(event):Observable<any>{
  return new Observable<any>(observer => {
    this.jsConnection.sobject("EBOX_Attachment__c").create({Name : event.selectedFile, Tender_Reply__c : this.tender.Reply.Id})
      .then(ret => observer.next(ret))
      .catch(error => observer.error(error));
  });
}

createAttachment(base64data, event, ret):Observable<any>{
  let name = event.selectedFile == this.$Label.EBOX_Other ? event.file.name : event.selectedFile;
  return new Observable<any>(observer => {
    this.jsConnection.sobject("Attachment").create({
        ParentId : ret.id,
        Name : name,
        Body : base64data.substring(base64data.lastIndexOf('base64,')+7),
        ContentType : event.file.type
      })
      .then(ret => observer.next(ret))
      .catch(error => observer.error(error));
  });
}

sendAttachToSF(base64data, event){
  this.createEboxAttachment(event).subscribe(
    ret => {
      this.createAttachment(base64data, event, ret).subscribe(att => {
        this.fileUploaded(att, event);
      });
    },
    error => this.toastr.error(error)
  );
}

uploadEboxAttachment(event){
  if (!this.jsConnection){
    this.jsConnection = window["jsConnection"];
  }
  let reader: FileReader = new FileReader();
  reader.onloadend = (e) => (this.sendAttachToSF(reader.result, event));
  reader.readAsDataURL(event.file);
}

fileUploaded(result, event){
  // this.popover.close(); would like to close popover here.
  this.onFileUploaded.emit(att); //emit event to parent component. works
}