That's an r/c serial protocol.
iBus is used by FlySky. It is similar to S.Bus, developed by Futaba and used by quite a few products.
Both run at relatively high speeds. S.Bus is inverted TTL serial, iBus is a bit friendlier and uses TTL serial.
So what? The one has absolutely nothing to do with the other until you write the code that makes them.
Work on decoding your iBus input. Work separately on how to control relays. When you can do each, combine them and do both.
It probably has been done, so either keep looking or learn how to write what will turn out to be a simple sketch, given the great starting point which will be the examples that you will find with any decent library.
a7