You might try the following steps to add a page number in the footer:

1. Go to the Layout tab and click on Page Number.
2. Select the location for the page number.
3. Choose the numbering style and how the pages should be displayed.
4. Select the page numbering style (such as 1, 2, 3 vs. i,ii,iii etc.)
5. Confirm the page number in the footer is present.

If you are having difficulties, you might switch to a different document editor, such as Google Docs, or consult a tutorial on the software that you are using.