Hi Mesdoua Abderrazek,
It is easy to play the P2P demo, please following the following steps:
1. download demo code into two FRDM-K64Fs via KDS:

2. put these two FRDM-K64Fs like below:

3. you may see the echo messages from the HyperTerminal :

Hope that helps,
Have a great day,
Kan
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------