...
You can choose which projects the project administrators can see the Administer Fields buttonwill have the Page Preview Section.
...
You can disable all projects with this button.
You can enable all projects with this button.
To disable the add-on in specific projects, choose these projects from the Enable in Projects: select and click this button.
To enable the add-on in specific projects, choose these projects from the Disable in Projects: select and click this button.
Enable/Disable Issue Types
You can choose which issue types will have the Page Preview Section.
...
You can disable all issue types with this button.
You can enable all issue types this button.
To disable the add-on in specific issue types, choose these issue types from the Enabled Issue Types list: select and click this button.
...
To enable the add-on in specific projects, choose these projects from the Disabled Issue Types list: select and click this button.
...