Mysql Permissions on a cpanel server

We have installed multi db. Created the databases. An now we need to assign permissions. We installed the multidb to use 4096 databases on a cpanel server.

However

We are having to add permissions for the single user to all the databases one by one.

Is there a way to add the user to all databases at once.

I have root access, I went to mysql and granted the user permissions to all the databases. Yet cpanel does not recognize it.