Error when completing BMITime

I’m getting error in Xcode saying

Undefined symbols for achitecture x86_64:
"OBJC_CLASS$_BNRPerson, referenced from:
objc-class-ref in main.o
ld: symbol(s) not found for architecture x86_64
clang:error: linker command failed with exit code 1(use -v to see invocation)

Is there any way i can upload image to show the whole error code.

That error means the linker could not find the BNRPerson class.

Make sure that BNRPerson.m is being compiled.

There is no need to upload an image to show the error. You should be able to copy and paste the text of the error.

Hi sorry for asking but how do i make sure the file is compiled? What i did is just press the run button.is that all to compiled the file?