As only licenced users / members can download version 3.x, TR will check for new modules on the Update Centre (Tools, Plugins, Settings tab, and make sure you have an Update Center with the URL set to: www.trgtd.com.au/tr/updates/3.7/updates.xml and that it is checked as active).
Initially, TR is set-up to check for updates every 2 weeks. You can change the frequency under Preferences (Mac) or Tools/Options (Windows or Linux)/Miscellaneous/Application Tab.
To check at any time, you can go under Plugins, Installed Tab and press the Reload Catalog button.