In the Insert Module click on Insert in the Pages section. 
The window which opens is split into several sections. You’ll find a description below.
Source section:
This section will allow you to choose the pages you would like to insert.
You will have the option to insert blank pages into your document. Change the number below of Blank page in order to insert that many blank pages into your document. You can also set the page size by clicking on the dropdown. 
You can also choose to insert another file into your current document by clicking on From File. Click on the … in order to browse your computer and find the file. You can also pick the page range of the file you would like to import. 
You can also choose the Duplicate pages option if you would like to duplicate current pages in the document. Choose the page range you would like to duplicate from the existing document. 
Place At section:
Now you will need to decide where the pages should be inserted. You can choose to place the pages Before or After any page in your document. Decide where the page(s) should be placed and click on Insert. 