[Hosting] Issue with JetPack Publicize connections.

When I connect social media accounts using JetPack [JetPack > Settings > Sharing > Publicize connections > Connect your social media accounts], it faild and returns this error:
500 status code for “POST /sites/167106878/publicize-connections/new”

But it is connected when I disable WAF on my hosting. I would like to know which IPs should I whitelist.