Can’t connect social account with publicize option

I’m creating a new blog website for my site, but I’m not able to connect my social accounts with publicize option in Jetpack. when I try it throws this error

500 status code for “POST /sites/160069241/publicize-connections/new”

I have already contacted my hosting provider and confirmed xmlrpc is enabled on my site. Your help would be much appreciated.

The page I need help with: [log in to see the link]