Step 1: Click on the Settings icon on the left navigation bar.

Step 2: Click on the Page Numbering Format.

Step 3: Choose your desired page numbering format.

Step 4: The page numbering will now appear on every page. If it is not center aligned, by default, page numbering will appear alternately in the left bottom and right bottom part of your page. So when you publish your book, page numbering will not be a problem.

Step 5(Optional): You can also center-align your page numbering by clicking the center-align switch.

Play around on the settings to meet your desired layout of your page numbering.