Having issues importing custom Jira Gadget into Confluence

I’ve been trying to get an external Jira Gadget added to the Confluence macro list following this wiki guide How to bring JIRA and JIRA Agile Reports into Confluence | Confluence | Atlassian Documentation but it seems to me that the UI has changed and some of the settings pages no longer exist, specifically the Add Gadget page.

Anyone have any ideas how to add external gadgets now?