Add your Readwise API key in the plugin settings page. You can acquire a Readwise API key by following these instructions.
On your first time using the plugin, you should use the Readwise Sync All command to load all of your existing highlights into RemNote. You can find this command in the Omnibar by pressing ctrl/cmd+k and searching for "Readwise Sync All".
If you have a really large Readwise collection, this could take up to 10 minutes. Please be patient :)
While the initial sync is running, don't refresh the page or close the tab.
Once the initial sync is done, future syncing will happen automatically in the background every 2 minutes.
Details
Readwise books are stored under a Top Level Rem called "Readwise Books" - please don't rename, move or delete this document otherwise the plugin won't be able to find where to save your highlights!
Readwise highlights are stored as children of the Readwise book they belong to.