How to I use No wildcard ssl on WpMultisite

Hello I buy ssl certificate but not wildcard and I have wordpress multisite and my user have subdomain , can not use ssl certificate

I want all administration operation work on the main domain for ssl work

sample : user admin work under “user.mainsite.com/wp-admin” and no wildcard ssl not working , But if user can administration on the main domain ” mainsite.com/wp-admin” ssl work Maybe ? Sorry for very bad english