Delete Template
You can delete the created Jira issue template in Easy Templates for Jira app.
To delete template
Go to Manage Templates
On a Jira Cloud
If you are a System Admin - go to Apps → Easy Templates
If you are a Project Admin - go to Project Settings → Apps → Easy Templates
On a Jira Data Center
Go to main NavBar Projects ➔ "Manage templates"
Find the template in the list and click on “…” 3-dot menu
Click “Delete”, after confirmation - template will be removed from the system.