ESP-Karajan is a kind of operating system for the ESP devices, taking away unproductive tasks of initializing the processor, WiFi connection, the displays, online dashboards, the measurement chips, the communication between ESP devices and the connection to a remote PC.
On ESP32 only, I could not find any working code to forget the WiFi credentials.
Of course one can erase them upon compiling, but I have the "X" menu to erase them by program.
That works only on the ESP 8266.
After a reboot WiFi, is re-established from EEPROM only if previously the credentials came from SmartConfig.
When the credentials came from the sketch, they are not stored, despite of these lines: