Updating Pro version of plugin to latest version and enabling auto-updates

I recently purchased the Pro version of this plugin (WordPress Fulltext Search Pro) with a two year license. I tried seeking support via the live chat tool and Contact Us page on fulltextsearch.org while logged into my account without receiving any response.

Per the description provided on www.remarpro.com, the Pro version of this plugin includes “Regular automatic updates (it works the same way as WP repository updates)”. On fulltextsearch.org the Pro plugin is shown to receive “All Updates”. However, the current version of the plugin available for download under the Downloads & Keys page when logged into fulltextsearch.org after purchasing a license key is 2.46.180. The 7-day trial version of the Pro plugin available for download is 2.49.200 prior to purchasing a license key. Version 2.46.180 appears to be 3 years old according to www.remarpro.com.

How can I obtain the latest version of the Pro plugin (is this version 2.46.180, 2.49.200, or something else?) and how do I enable auto-updates for this plugin within WordPress? There does not appear to be any way to enable auto-updates within the WordPress plugins pane, as is possible for other plugins. Manually checking for updates and manually updating the plugin on a regular basis will be challenging.

I am concerned that a lack of updates to the Pro version of this plugin will result in an insecure plugin and one that will eventually cease functioning as WordPress continues to be updated.

Thanks for your assistance.