Do the steps in this topic: Publish to PDF and Print.
Then, do these steps:
Click
Save PDF.
The Save As dialog box appears.
Do these steps in the Save As dialog box:
Navigate to the folder where you want to save the file.
Edit the file name (optional).
Do not change type of file. The filename extension needs to be .pdf.
To distinguish the files, the default file names include "Pages" for Simple, "Cover" for the Booklet Cover and "Inside" for the Booklet Insides.
Click Save.
PDF files are automatically compressed using Ghostscript (https://www.ghostscript.com/).
https://community.software.sil.org/t/how-to-compress-a-bloom-pdf/24 might help you if you have a huge PDF file that is problematic.