Steps to follow when you have already a template created and active, but you want to disable it.
First step:
To locate the Notification Center, you need to hover your cursor over the left part and access the Navigation Bar, then go to the Messages section, and there you will find the Notification Center.
Second step:
Identify the template that you want to change the status for.
3rd step:
After identifying the template, click on the Edit button of the template.
Final step:
At the bottom of the window that will pop up, you will find the toggle where it says Disable - Active, where you just need to switch it to Disable or Active depending on what status you want the template to have.