JIRA Service Desk 2.0 and later can be used with two different tier of licenses; Users based license (Version 1 license) and Agents based license (Version 2 license). There are certain differences on how JIRA Service Desk behaves, based on the license type it is using. This page covers the Frequently Asked Questions on JIRA Service Desk 2.0 and later, in regards to the license type.
What type of Service Desk license am I using?
You can check from the Manage add-ons page to determine what license type you are using. Go to 
> Add-ons > Manage add-ons (on the left sidebar) > Refer to JIRA Service Desk and expand the box. You can refer to the license details whether you are using the Agents based license or Users based license. See the attachment below:
Users based license
Agents based license
What is Evaluation License considered as?
Evaluation license for JIRA Service Desk 2.x is considered as Agents based license. Thus, it will give you the add agents, public signup, and other features available for JIRA Service Desk 2.x with Agents based license.
Why can't I add agents (under People tab)?
The functionality to add agents is available in Service Desk 2.0 and later with Agents based license, based on Add your service desk agents documentation. You will see the people tab looks like the below image. If you see a different interface of People tab, kindly check your license type (Refer to Question "What type of Service Desk license am I using?")
Why can't I enable public signup?
Public signup is a feature available in Service Desk 2.0 and later with Agents based license, based on Configuring public signup documentation. You can enable the public signup either from Customer page (under People tab) or Configuration page (under manage add-ons page).
If you'd like to enable from Customer Page, then go to your Service Desk project > click on People tab > click on Customer > click on Everyone can access > and tick on "Anyone can signup for a customer account on my Customer Portal" as shown below:
If you'd like to enable from Configuration page, then go to > Add-ons > click on JIRA SERVICE DESK: Configuration (on the left sidebar) > Refer to Public Signup section and turn it on, as shown below:
Why does my PEOPLE tab look different (from the documentation)?
Below is the interface of People tab if you are using Users based license
Below is the interface of People tab if you are using Agents based license
Why does my COMMENT box look different?
Again, it is again due to the license tier.
Below is the interface of Comment if you are using Users based license
Below is the interface of Comment if you are using Agents based license
