You need to be a Jira administrator in order to install UpRaise for Employee Success.
There are multiple ways in which it can be installed:
By searching the Marketplace from within Jira
As a Jira administrator, navigate to the administration page and click on “Add-ons” in the top menu bar.
Now select the “Find new add-ons” menu item and enter “UpRaise for Employee Success” in the Search box on the left.
In the resulting search, select “UpRaise For Employee Success” and click on the "Buy Now" or "Free Trial" buttons. Clicking on one of them will take you to https://my.atlassian.com where you can either enter your User ID/password or create a new account. This will give you a free 30-day evaluation version or let you buy licenses.
The software will now be installed and the license key will be automatically added to activate it.
By clicking on the “Try it free” or "Buy it now" button in the UpRaise For Employee Success page on the Atlassian Marketplace