Second note: the local website has to be reached from every browser...
Third note: there is no problem to connect a smartphone to the ESP.
I just tried it to get access to the webpage. Here are some new facts:
I have codes the ESP's SSID with the IP Adress, in other words: if you do a wifi scan, than you are able to see a SSID called "(IP unset)".
you can connect to the SSID, so no problem with that
you can also access to the website with IP 192.168.4.1
Why does not show up at the SSID ? two month ago, it worked. two month ago, I did put the IP directly to the SSID. It worked than. you could see as SSID this: 192.168.4.1 <-- so it worked
My only fear ist, that this IP adress could change sometime. So agian: is there a way to make it steady ? The best way would be, to reach it via hostname, for example: http://esp