Arduino HM-10 Bluetooth with iOS : Connected, but it doesn't send values

I'm trying to make an iOS (SwiftUI based) app to connect the arduino and send the current latitude value of ios to arduino. I successfully made the view that allow user to select the bluetooth device, and the UUID/name of the device is successfully displayed. Also, the arduino device detects connection (I used LiquidCrystal to display serial and it says "OK+CONN" and "OK+LOST" if connection was lost.), but when I click "fetch location" button, nothing happens on arduino side.

The code is in stackoverflow due to character limits: https://stackoverflow.com/questions/76752529/arduino-hm-10-bluetooth-with-ios-connected-but-it-doesnt-send-values

Arduino HM-10 Bluetooth with iOS : Connected, but it doesn't send values
 
 
Q