Burndown report empty

Burndown report empty

Hello all,
I'm new to Zoho analytics, and I would need to simply use the default burndown chart.
I follwoed all steps described here :  https://www.zoho.com/analytics/setting-up-zoho-projects-analytics-add-on.html : please see the last  slides at bottom page.
So:
- I added to the burn down milestone entry table - template my milestone (which is a sprint), like that

- According to the tutoial, the milestone burndown calculation query should be filled automatically, which is not the case 
- And as a consequence the burn down rfeport is empty, the dropdown list milestone name is empty.

Can someone could explain me where I made something wrong?
Thanks in advance
Regards
Franck