Multisite domain mapping

Hi, we need add park domain to cpanel to make domain working?

I want to map my subdomain to external domain. ns server already point to my hosting. Before this, te external domain is add on domain on my same hostin. I try move to multisite. So i create subdomain, import. Delete the sigle site installation and domain, And try to map that domain. This error occur.

Here my error

Can help me