go to the Project menu and click the Project settings menu option;
use Ctrl+Alt+P shortcut.
Project settings dialog should appear. On the left side of it go to DOCX export.
DOCX document metadata
Use this section to enter the DOCX file metadata, such as Title, Subject, Author, and Keywords. This data will be shown in the properties of the exported DOCX file, but it won't affect the document layout or visible content.
Use this section to specify dimensions for DOCX pages. The list of page formats are taken from the settings of the printers connected to the computer (including virtual ones).
To set landscape orientation, select a paper format from the drop-down list, the name of which contains the word "Inverted" or "Rotated". For example, for A4 landscape orientation, select"A4 Rotated".
If you need to use landscape orientation for a page because of an image in it, consider rotating the image 90 degrees in a third-party image editor and paste this rotated image into Dr.Explain.
If that doesn't suit your needs, you can add image as-is, and then set landscape orientation for individual pages of the exported DOCX document by editing this DOCX document in a third-party DOCX editor application.
Enable this checkbox to make each section begin on a new page.
If you prefer to manually control which topics start on a new page, clear this checkbox. In that case, you can specify that the following topic should begin on a new page by manually inserting a page break at the end of the current topic.
If you clear the checkbox and then insert a page break at the very beginning of a topic, the page number in the table of contents of the exported DOCX file may become misaligned: it will show the page on which the previous topic ends (since formally the topic starts with a page break, and that break is on the same page where the previous topic ends).
button in the 
