When we want to play youtube in an ionic project. Simply using

<youtube-iframe-player></youtube-iframe-player>

Issues

It works great during development, and also on Android. However once it is tested in iOS, it shows a blank page with

Unable to post message to https://www.youtube.com. Recipient has origin file://

Solution

To Solve this, include the plugin cordova-plugin-whitelist

cordova plugin add cordova-plugin-whitelist

then add <allow-navigation href="https://*youtube.com/*" />

<plugin name="cordova-plugin-whitelist" spec="~1.3.0" />
<allow-navigation href="https://*youtube.com/*" />

Enjoy and hope this help!