What didn’t work with this tutorial? The key is this…
Check the movement on the client (OnTick in this case). Pass the pitch to ServerReplicatedRotation. Then have ServerReplicatedRotation pass this pitch information to MC_ReplicateRotation which will multicast that pitch to everyone where each instance of the multicast will set the desired rotation of whatever.
Something to check is that whatever you attempting to replicate needs to have its Replication check box checked in details.