When I add-on a domain it don’t display it on the right I changed the dns servers to the same has the main website so how do I verify that it added it?

Also my previous hosting company uses cpanel can I do a full backup and restore it on this server ? Or will it cause errors?

Open a trouble ticket and notify your main domain name and addon domain name.

We apply our own soft for backup. If you want to extract some files from backup contact our support.