How to use the signature_pad/dist/signature_pad.js function in signature_pad

attach(element) {
    this.loadRefs(element, { canvas: 'single', refresh: 'single', padBody: 'single', signatureImage: 'single' });
    const superAttach = super.attach(element);

    this.onDisabled();
    // Create the signature pad.
    if (this.refs.canvas) {
      this.signaturePad = new SignaturePad(this.refs.canvas, {
        minWidth: this.component.minWidth,
        maxWidth: this.component.maxWidth,
        penColor: this.component.penColor,
        backgroundColor: this.component.backgroundColor
      });

      this.signaturePad.onEnd = () => this.setValue(this.signaturePad.toDataURL(), {
        noSign: true
      });
      this.refs.signatureImage.setAttribute('src', this.signaturePad.toDataURL());

      // Ensure the signature is always the size of its container.
      if (this.refs.padBody) {
        this.addEventListener(window, 'resize', _.debounce(() => this.checkSize(), 100));
        setTimeout(function checkWidth() {
          if (this.refs.padBody && this.refs.padBody.offsetWidth) {