Fill in your contact and (if required) your payment details and click on "Complete Order".

The plugin will automatically be added to your Creative Cloud account and installed into Adobe Photoshop for you. In most cases you will not need to restart Photoshop, but if the plugin does not appear please quit and open it again.

If you have any problems, please let me know, but all of the installation process is in Adobe's marketplace code, so you may find a solution at https://helpx.adobe.com/creative-cloud/kb/troubleshoot-common-addon-installation-issues.html