1. First, open the article to which you want to add literature, and select the paragraph to which you want to add literature.

2. Click the citation option above, and then click Insert Endnote. After inserting the endnote, we found that the note was "I" and we could change it.

3. Click the footnote drop-down option in the reference option to open the footnote and endnote setting menu.

4. In the number format, select the number form, and then click "Apply" to change it to a number.

5. Let's put brackets around the numbers, and then press "Ctrl+H" on the keyboard to open the "Find and Replace" menu. Enter "e" in the search content and "&"in the replacement content. Special symbols are on the numeric keys of the keyboard. Click "Replace All" after entering.

6. At this point, comments have been added, and you can directly type or paste the contents of the document.