Pre-requisites:
'Admin' permission on the project template where a workflow trigger needs to be created.
Below are the steps to create a workflow trigger for custom objects in a project template:
1. Navigate to 'Workflows' tab and select the project template.
2. Click on 'Create Trigger' button to start creating a trigger event.
Alternately, right click on project name and select 'Create Trigger' option.
3. Follow the step to create a workflow trigger for custom objects in a project (step 3).
4. Click on 'Create' to complete creating a workflow trigger.
Next Collection: Left Hand Menu Options in 'Workflows' tab