Log in to your Confluence instance.
Go to the space in which you want to use macro.
Open a page to Edit (or create a new page).
Type / and the beginning of an element (tool or things in the insert menu) to see a list of suggestions and select Static content macro. OR
Click ➕ on the editor at the top > View more and select Static content macro.
Select template which you want to use.
The macro with template is added to the page. You can change it for another one by clicking Edit (pencil icon) on the particular macro. To remove one, click Delete (bin icon).
If you want to change the content of the template or need a new, firstly contact a user with the Confluence Administrator space permission.