Error message when compiling for Arduino Uno WiFI

these are my error messages:
Arduino: 1.8.19 (Windows Store 1.8.57.0) (Windows 10), Board: "Arduino Uno WiFi"

In function 'void setup()':

m2-lesson4:195:4: error: 'Serial1' was not declared in this scope

Serial1.begin(9600);

^~~~~~~

(1)\m2-lesson4\m2-lesson4.ino:195:4: note: suggested alternative: 'Serial'

Serial1.begin(9600);

^~~~~~~

Serial

In function 'void do_Uart_Tick()':

m2-lesson4:210:6: error: 'Serial1' was not declared in this scope

if(Serial1.available())

  ^~~~~~~

210:6: note: suggested alternative: 'Serial'

if(Serial1.available())

  ^~~~~~~

  Serial

exit status 1

'Serial1' was not declared in this scope

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

4 posts were merged into an existing topic: Mega to r4 code conversion?

Exactly which board have you got selected in the IDE ?