Reading data received from Nextion on Serial Monitor

Other Hardware Displays
9

Tx for your relies and help.
I would like to try out all your suggestions but to avoid too much confusion I would like to go through each suggestion one at a time'
Perry i have downloaded your suggested sketch but when I attempt to compile i get the following error;
C:\Users\Farticus\AppData\Local\Temp\arduino_modified_sketch_320792\sketch_oct16a.ino: In function 'void RxNextionData()':

sketch_oct16a:30:10: error: 'Serial1' was not declared in this scope

while (Serial1.available() > 0) {

      ^~~~~~~

C:\Users\Farticus\AppData\Local\Temp\arduino_modified_sketch_320792\sketch_oct16a.ino:30:10: note: suggested alternative: 'Serial'

while (Serial1.available() > 0) {

      ^~~~~~~

      Serial

exit status 1

'Serial1' was not declared in this scope

I am using a Uno for this sketch