Moneydance can add extensions using the built-in extension manager. 

Extensions can be accessed by navigating to Extensions > Manage Extensions.

The Manage Extensions window includes three tabs - Available, Installed, and Updates.

You can install new extensions, view and update your installed extensions, or remove unwanted extensions.

Once installed, you can access any extensions from the Extensions menu, where the installed extensions will be listed.

If you have purchased Moneydance from the Mac App Store or Microsoft Store -

You can install extensions from the Extensions page on our website.

Click on "Download" for the appropriate extension - this will download a .mxt file.

Open Moneydance and drag the downloaded .mxt file onto the Moneydance program window.

The "Add Extension" window will appear, and you should select "Install Extension".

Once installed, the extension will then be available within the Extensions menu.