Problem to make async part of collective.documentviews work

Hello,

I am unable to configure my buildout.cfg with an async add on compliant with collective.documentviewer.
I tried async and celery but i can't found my problem.
Can you show me a plone5 buildout.conf that i can run successfully and works with documentviewer and an async module ?

Best Regards,

And your specific error/problem is?

-aj