Send a message with LoRa Esp32

Hello there,
I'd like to input a message that will be send from a LoRa module to another,
(The modules are like this one : )

I'd like to display the message on my Sender module, then send it, and when my receiver module gets the message, it displays it on its screen and the serial monitor

however I can't manage to send the input; I can save it as a String, then when I want to display it they say I can't use the function to display with a "String&" in the parameters (I can display the message when I put quoted text in parameters )

Could you help me send and receive those messages ?
I've attached the code, you can give it a look if you want
Thanks for any hint you could give me

The next step is about the encoding,the only thing I get by sending a message is a long int, but I'll need to fix the message-sending-thing before I can worry about this

EDIT: There's a "counter++" in the code, you'll have to remove it if you wanna test things, it was from another test but I don't need it anymore

LoRaSender2.ino (1.18 KB)

  u8x8.drawString(0, 3, rx_String);

Should these be rx_str instead of rx_String as the example code you supplied does not define rx_String anywhere.

Yup I corrected that right after I asked the question, thanks for the notice anyway

So I managed to remove all the errors now,
I converted the String to a Char array and it worked,
I'm uploading the code if you wanna see
Now there's another error, the program doesn't seem to wait for me to enter any String and directly crashes
I'm gonna try fixing this

LoRaSenderReceiver.ino (1.21 KB)