Apple4787 wrote:
My keyboard is an English type. i don't have the Extra key
It's not "English", it's American. European English keyboards have the Extra key.
As I already said:
"The only easy way to make a zero with it is to set your Input Source to Hungarian Qwerty and then do ALT/Option with the key under ESC.
You need to make sure that Hungarian Qwerty is on the list at system settings > keyboard > text input > edit > input sources. If Hungarian is there, use the minus button to remove it."
You should try that. If you don't understand part of the instructions, let us know.