Sg-jira-bridge field confusion?!

I walking through the Quick Start Guide for SG Jira Bridge and attempting to create a project.
The #required-fields table has some contradicting terminology.
For one I’m unsure how to name the “Jira Key” fields as they each need to be unique.
Also, the “Required Fields” table references columns of Entity Type and Data Type.
Which does not seem consistent, I can choose an “Entity Type” that is a Project Field.
Or “Data Type” that is a File/Link but not both.