Wpa handshake

stuck on the Capturing The Handshake course and I’m not being able to receive a handshake. tho the target of deauth is working and I check the wifi turns off and on yet no wpa handshake was captured and I tried turning off the wifi manually also no handshake and turned the phone off and on for 100 percent to make sure the wifi wasn’t connected to the phone yet there was never wpa handshake received. though sometimes not always this show instead interface wlan0 down

It happens sometimes. The attack is not successful 100% of the time due to many issues like network signal, channel it is on, etc. You have to keep trying. Use different OS, try different wifi adaptors.