.db encryption key

I need to export my data with photos to another database system.  The only method seems to be to archive the database, change the file extension from .ninox to .zip, decompress the zip file and then find the photos in a "files" folder. and the data in a sqlite .db file.  The photos are not stored flat in the "files" folder.  Each photo is in its own numbered folder.   Presumably the folder number corresponds to a record id in the .db.

The .db sqlite file is encrypted.  I have sqlite libraries installed on my machine and would like to open the .db file in a python program so I can then programatically transform and load the data with photos into a mysql database.  How do I obtain the encryption key to my .db file to access my data?