Footnotes are only available with the "premium" edition. They consist of a reference in the text, the footnote number and the text layer, which is automatically placed at the bottom of the page with the reference.
You can create a new footnote with TextCursor.InputFootnote. After the creation of a header, footer, textbox or footnote texts you can use GotoBody() to return to the body text to create more text there. When editing the footnote, just press ESCAPE.