Please ensure you have updated to Astute Manager v2 before proceeding. An easy way to tell the difference is that v2 operates in a larger window, whilst v1 was constrained to a smaller, vertical window locked to the top right of the screen.
If you have previously installed the subscription plugins, you should see the Astute Manager menu bar icon (macOS) or Tray (Windows) indicate updates are available with a small red dot in the app icon as shown below:
Open the Astute Manager main window to discover what plugins have been updated:
Either install individual updates by clicking on the appropriate Update to vX.X.X button, or navigate to the Updates page and Update All:
Note that updates are only applied to the currently targeting installed version of Illustrator.
For more details on managing your plugins, please refer to the Plugin management options in Astute Manager page.