To send Now Playing metadata to Radioplayer using PlayIt Live you will need the Now Playing plugin. You can get this from https://www.playitsoftware.com/Plugins/View/NowPlaying
Click the downloaded file to install the plugin. Once the plugin is installed, on PlayIt Live, go to Plugins > Plugin Manager and double-click Now Playing.
Under the HTTP Web Request tab, tick the box Send now playing track via an HTTP web request. Then select POST as the method and enter the URL:
replacing <your rpuid> with your RPUID, e.g. 123456.
Your station's RPUID can be found by logging into my.radioplayer.org and going to the Station Overview:
On the Now Playing plugin, enter your Radioplayer Username and Password.
The plugin should look something like this:
Click Apply Changes. When a track begins playing the following text will be displayed on the plugin if the update was accepted:
Your currently playing track will then be shown on your Radioplayer player: