title: get url address for current spreadsheet
body: <p>I need to get url address of current Spreadsheet by script without fixed address like this</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>let curURL = "https://docs.google.com/spreadsheets/d/1mCcmko-FvmTTJn8RDhlfWE0AZYPKlUnskqlc4-eYrJ4/edit?usp=sharing";</code></pre>
  </div>
  </div>
  </p>
  <p>I tried to use this</p>
  <p>let curURL = ScriptApp.getService().getUrl();</p>
  <p>but I got empty value. Thank you for help!</p>