It seems al developers have to get a DUNS number, the new ones and the already existing ones.
As I understand it, a developer must leave a phone number and a mail-address so people can contact the developer.
The phone number is not what I want. What does this mean: Do I have to stop with putting the App on Google Play and only out it on my website for example?
Yes, if you absolutely can’t provide a phone number then that might be your only option.
I’ve seen the new statements about a DUNS number but haven’t delved into it yet. Do you have any idea if that number is going to be externally searchable? Sometimes these sorts of organizations want the phone number so that they can verify the developer is real, but they won’t pass it on to other people.
In that sort of situation I’m more comfortable providing a number in a Western country and/or with an expat who answers. In other cases we try to limit it to phone numbers of nationals. It’s fairly context dependent how we deal with it.