Error compiling for board Arduino Nano

i found an issue while i am uploadilng code. can u solve or help me.

RetroWatchArduino_u8glib_no_button.ino (28.7 KB)

Which IDE ?

Did you select the correct "FLAVOUR" of nano ?

Not really enough detail to do more than guess here.
Suggest you read the sticky posts at the top of the section.