I am trying to get a file from azure blob and sedn the file to nextjs frontend. However, my response comes as a string.

this is my controller function

  @Get('download/:id')
  async getDownloadedFile(@Request() req: JwtRequest, @Param('id') id: string,  @Res() res: Response){
    const blobName = `/chain/${id}`.toLowerCase();
    const container = req.authContext.id.toLowerCase();
    const downloadResponse = await this.azureStorageService.getFile(container, blobName)

      res.setHeader('Content-Disposition', `attachment; filename="file.txt"`);
      res.setHeader('Content-Type', 'application/octet-stream');

      downloadResponse.pipe(res);
      
  }

however on the frontend, the Content-Type is still application-json and the response comes as a string.