The Selenium Nodes are distributed through the following software sites (to see, what’s new, check out the changelog):
Make sure that you have a current version of the KNIME Analytics Platform. Copy the update site URL which matches your KNIME version from above.
Go to Install/Update → Available Software Sites, click on Add… and paste the update site URL. Save and close the preferences window.

Select Selenium for KNIME for installation. Restart KNIME when prompted to do so. After a successful installation, the Selenium nodes will be listed in KNIME’s Node Repository.

Navigate to KNIME → Selenium, click Enter … paste the license which your received via email, including the lines -----BEGIN LICENSE----- and -----END LICENSE-----. To try out the Selenium Nodes, request a free trial license which is fully functional for one month.
