Communicating Between Nextion 7' Enhanced to Mega 2560 and SD card Module?

Hi,
I Need Help to display Calculated Date-Time in Nextion HMI and save data input with keyboard in nextion in other page then saved them into sd card modul in .TXT via arduino.

*Here what i want to ask,
How to get data such:

  • RTC from Enhanced Nextion to arduino (.ino code) and what .hmi code(variable etc?)
  • Data from textbox (.ino)
  • Acces .txt file (name,no,time from enhnanced rtc) from sd card then send it to nextion (.ino)

Input from nextion => send data to arduino => save to sd card => display sd card data to nextion
-I got problem in communication, how to accessing between them.
-i have followwing sd card tutorial from arduino forum but still can't create the .txt file in sd card. stuck in SDCard Initialized

Thanks