Installing 

To install Markdown Macro for Confluence Server/DC, take the following steps:

1. Log in as a user with the Jira Administrators global permission.

2. Click the admin drop-down and choose Atlassian Marketplace and the Manage apps screen loads. Tip: Use Keyboard Shortcut instead: g+g and start typing “manage...”.

3. Click Find new apps on the left-hand side of the page and locate Markdown, HTML, PlantUML, LaTeX, Diagrams, Open API, Mermaid via search.
The appropriate app version will appear in the search results.

4. Click Try free to begin a new trial or Buy now to purchase a license for Markdown Macro for Confluence Server/DC. 
You'll be prompted to log into my.atlassian.com. Once logged in, Markdown Macro for Confluence Server/DC will begin to download.

5. Enter your information and click Generate license when redirected to my.atlassian.com.

6. Click Apply license.