Is there any way to copy the program which already loaded in a STM8 chip to another ?

[JCha.200]

I would like to copy a STM8 chip exactly same as the original and the new one should be running . If you show me the way how to do it then I'll be appreciated. What interface can be suitable among the UART, ISP, I2C ? If you provide some sample code then it'll be much more helpful.

Thanks.