All looks fine except empty chart :-(

hi. i struggled 3 days to make this work and finally i managed to install plotly, make the module and credentials accept to connect.
finally all seems fine and even on execution the browser opens automatically and new files appears in home.

my LAST problem is that the charts remains desperately empty.
begging for help.

the script and wiring i use: http://www.instructables.com/id/Real-Time-Graph-Ultrasonic-Sensor-With-Raspberry-P/
except i do it on raspberrypiPi3

on the shell terminal i see the following:

pi@raspberrypi:~ $ python3 /home/pi/Documents/testit.py
plotly cred checking
Ultrasonic Measurement
inside measure
Distance : 2419.0
(epiphany-browser:1692): WARNING **: Error retrieving accessibility bus address: org.freedesktop.DBus.Error.ServiceUnknown: The name org.a11y.Bus was not provided by any .service files
inside measure
Distance : 2409.1
inside measure
Distance : 2408.0