How to save JSPDF generated pdf in Angular assets folder?

Question

I want to download my JSPDF generated PDF on Angular's assets folder. By default is getting downloaded in programs folder in disk-E. What should I need to change in my code. Here is my code:

  private download(): void {

    var pdf = new jsPDF("p", "mm", "letter");
    let options = {
      pagesplit: true,
      background: '#fff',
      format: 'PNG',
      padding: 0,
      // margin:{top: 10, right: 10, bottom: 100, left: 10, useFor:'page', 
      //         width: pdf.internal.pageSize.width, 
      //         height: pdf.internal.pageSize.height}
    };
    pdf.internal.scaleFactor = 3.20;

    const input = document.getElementById("content");
    html2canvas(input)
      .then((canvas) => {
        pdf.addHTML(input, 0, 0, options, () => {
            pdf.save("assets/invoice" + new Date() + ".pdf");
          }, {top: 10, right: 0, bottom: 10, left: 0}
        );
      });

  }

As you can see in code I saved file using pdf.save() method and thought assets/invoice will go to assets folder of Angular but it didn't work, it created file with name assets_invoice.pdf in program folder.

Any help will be greatly appreciated.