URGENT 2 radius servers

RouterOS The User Manager
1

Hi,
Is there a possibility for mikrotik to use more than one radius server, such as that if a user cannot be detected on 1 radius server/usermanager that it automatically is directed and/or to be detected on another radius server/usermanager?
Thank you.

2

Once you get an ACCESS-REJECT no further RADIUS servers are checked.

3

how about realm ?
how to use it ?