Global Issue Templates
If you want to reuse Issue Templates across multiple Jira projects, you can create Global Templates. This feature requires admin or site admin permissions, and it is generally designed for Jira admins.
If you are project admin or work on only one project, please refer to Create an Issue Template.
For creating global templates:
Go to Apps → Issue Templates from top menu.
Click on Add template button and create template window will appear.
Similar to project templates, you can create a template per issue type.
Using Global Issue Templates
Unlike project templates which are immediately activated in the current project, global templates need to be enabled in each project separately. This is one time operation and can be done by project admins as well.
If you edit a global template, it will be reflected to all assigned projects. Project admins cannot edit global templates, they can only enable or disable global templates from a project.
In order to enable global templates in a project:
Go to Project Settings → Apps → Issue Templates
Find Global Templates and Action (…) on the right
Manage Global Templates
Project admins can manage global templates from top menu Apps → Issue Templates. Use Action (…) to edit or delete the templates.