Insertion method:
In Page view, click where you want to insert the annotation reference tag.
On the References tab, in the Footnotes group, click Insert Footnote or Insert Endnote.
At this point, a horizontal line and a serial number appear at the bottom of the current page. Because it is the first footnote, it is 1.
We can enter the text to be annotated after the serial number.
Back to the text, a serial number like superscript 1 appears where the footnote is to be added.
Place the cursor on the footnote number to display the contents of the footnote, and double-click to jump to the footnote at the bottom of the page.