test.html

<html>
  <script src='./dist/print.min.js'></script>
  <script type='text/javascript'>
    function printPdf() {
      printJS('/test.pdf');
    }

    function printHtml() {
      printJS('test', 'html');
    }

    function printJson() {
        let data = [
            {
                test1: 'Test1 string',
                test2: {
                    a: 'Test2 object, a property',
                }
            },
            {
                test1: 'more Test1 string',
                test2: {
                    a: 'more Test2 object, a property',
                }
            }
        ]

        printJS({printable: data, properties: ['test1', 'test2.a'], type: 'json'})
    }
  </script>
  <body>
    <section id="test">
      <h1>Print.js Test Page</h1>
      <button onClick='printPdf();'>
        Print PDF
      </button>
      <button onClick='printHtml();'>
        Print HTML
      </button>
      <button onClick='printJson();'>
        Print JSON
      </button>
    </section>
  </body>
</html>