It is very important to save WiFi setting (SSID/Password) and server address in permanent so it can autometically reconnect with WiFi on next start.
StorageIO class provide an easy interface for EEPROM.
#include <StorageIO.h>
void setup(){
Serial.begin(9600);
while(! Serial);
StorageIO rom;
rom.writeNextString("Hello ");
rom.writeNextString("World");
rom.reposition();
Serial.print(rom.readNextString());
Serial.println(rom.readNextString());
}
void loop(){}
Note: Try to minimize the number of writes on EEPROM because it reduces its life