Virtual Relays behave – and are configured – exactly like Physical Relays, but there are two differences: their ID uses a different letter (“O“), and the number of virtual relays available is 128.
Virtual Relays are ID’ed from 1O1, 1O2, 1O3, up to 1O128. The letter O stands for Output, even though it is “virtual”.
Please see this article for details on how to configure Relays.