You must have the Jira Administrator rights to be able to carry out the instructions on this page. You can learn more about this here.
Please take a look at the Supported Platforms section as well.
Step 1. Go to the Jira Manage apps section and in the opened window click on “Find new apps” field.
Step 2. Enter “Smart Git Integration for Jira Alpha Serve” in the search field, press Enter and find the application in the search result.
Click on it.
Step 3. Click Free trial to get a 30-day free trial license.
Step 4. In opened window click the Accept & install button. You'll be informed about the plugin installation process started.
Before the Free trial started, you’ll be proposed to Get a license by Generating and Applying it.
You’ll be notified about successful installation.
You can easily access Smart Git Integration for Jira from the Manage apps section.
You can also install Smart Git Integration for Jira directly from Atlassian Marketplace by visiting the application product page here.