Adapted from official source
The esp-idf version of the current project is ESP-IDF Release v4.4.1
# csi_send
cd csi_send
idf.py set-target esp32
idf.py flash -b 921600 -p /dev/ttyUSB0 monitor
# csi_recv
cd csi_recv
idf.py set-target esp32
idf.py flash -b 921600 -p /dev/ttyUSB1