How to add initcontext parameters to Aurena URL

I tried to use the 'initcontext' of the 'page' to define url parameters. The problem is, that I have no idea how to put the parameter into the url. According to this link, I've built this so far:

page CCtiLandingPage using PhoneNumbers {
   initcontext PrepareNumber;
}

initcontext PrepareNumber {
   parameter NumberRaw Text;
   init command {
      execute {
         info("${NumberRaw}");
      }
   }
}

The most obvious variant didn't work:
[...]/main/ifsapplications/web/page/CCtiLandingPage/CCtiLandingPage?NumberRaw=’123’

As a result, I get an empty info box.
Can someone tell me how to write this URL to pass the parameter?

IFS Aurena framework version: 10.13.19.0
IFS Aurena client version: 10.13.120.0
IFS OData provider version: 10.13.1.0