You can test fully functional TFS4JIRA plugin for 30 days by obtaining an evaluation license. The easiest way to do it is to navigate to Jira Manage Add-ons (Manage plugins) administration page, locate the plugin in User-installed plugins section and click Free Trial button. You will then be redirected to my.atlassian.com site, where you can obtain an evaluation license.
Please bear in mind that while evaluating TFS4JIRA Cloud Native Synchronizer you are entitled to synchronize up to 100 unique items per license. In order to perform synchronization of more items please upgrade to paid version or contact our support team to get more details.
Buying TFS4JIRA license
You can buy a license by clicking Buy Now button on Manage add-ons Jira screen (see screenshot above) or you may go to plugin's Marketplace page and start from there.