Safari cannot open...

Hi. I am a bit perplexed here. TeamViewer Quicksupport promised to open the possibility to mirror on my iPad pro the screen of my iPhone 8. But I just can’t make it work. After I start broadcasting from my iPhone, when trying to type the access code ID at start.teamviewer.com on my iPad all I get is an error message, Safari cannot open the URL. Did I get something wrong? The procedure seemed pretty simple.