Turn on Show/Hide formatting marks
Place the cursor just before the page break
Press Delete
Or place the cursor just after the page break
Press Backspace
If it is a manual page break, select the page break line and delete it
If it is a section break, delete the section break carefully
If the page break is caused by paragraph settings, open Paragraph settings and remove Page break before
If the page break is caused by content spacing, reduce spacing or remove extra blank paragraphs