No sound be Realm Royale?

My friend and I want to play Realm Royale, he plays on the ps4 and I on the PC. I hear him on voice chat, but he doesn't hear me.

Can be due to the micro or the settings of the micro. In the general setting of the microphone you can say how loud the microphone should be. Otherwise it can be that your friend has set the voicchat volume to 0 at realm royal