Issue Template for Jira - Summary & Description Templates is available on Atlassian Marketplace. You can try the app 30 days for FREE!
Go to Issue Templates Pro for Jira on Atlassian Marketplace
Click on Get it now
Choose your instance and click Install app
The app will be installed in your Jira instance.
If you are not the Jira admin, you can request the app instead, following the same process above. Your Jira admin will be informed with the request to install this app.
Once the installation is complete, you can add templates to your Jira project: Using Issue Templates in Jira