Hey @Sinzore
When you deploy your site, the contents are deployed to home/site/wwwroot
. Depending on where your db file is, it would be relative to that directory. Have a look at Understanding the Azure App Service file system to learn more.
However, I will caution that you it is not recommended to use this file to store any application related data. Sqlite utilizes file handles and locks so if you were to ever scale your application, you could run into lock contention.