fileIT makes use of an Apex trigger to handle sharing in Dropbox. Triggers are included for standard objects, Accounts, Contacts, Leads, Opportunities and Cases.
If you want to follow Salesforce security model on custom objects then you will need to add an Apex trigger yourself to call fileIT to make the changes. This will need to be done within a Sandbox and will need a test class before it can be deployed. Only certain editions allow you to write code.
Here we show the code that you need to have in your trigger, we do not detail how to develop it in the sandbox. The trigger should only execute on the after update event calling this code in other events will cause an exception to be thrown.
Copy and paste the code below replacing the green insert name text with your object API name for example project__c