Enum ParagraphHeading

const body =     DocumentApp.getActiveDocument().getActiveTab().asDocumentTab().getBody();  // Append a paragraph, with heading 1. const par1 = body.appendParagraph('Title'); par1.setHeading(DocumentApp.ParagraphHeading.HEADING1);  // Append a paragraph, with heading 2. const par2 = body.appendParagraph('SubTitle'); par2.setHeading(DocumentApp.ParagraphHeading.HEADING2);  // Append a paragraph, with normal heading. const par3 = body.appendParagraph('Text'); par3.setHeading(DocumentApp.ParagraphHeading.NORMAL);