unable to add site to the hub

Getting error "Your server had a problem connecting to WPMU DEV: "HTTP Error: 403 "Forbidden"". Please try again.

If this problem continues, please contact your host with this error message and ask:

"Is php on my server properly configured to be able to contact https://premium.wpmudev.org/api/dashboard/v2/ with a POST HTTP request via fsockopen or CURL?"

The hosts responded with...
I've checked and this issue seems to be caused by blockage of the IP address of your website in the WPMU servers. Could you please contact them and ask them if they can whitelist IP