volume on tv does not work with kodi

Just got a firestick with kodi on it ( the only thing on it I am using ) and when i watch something on it, i cannot control the volume with the tv remote. It wont turn or up or down. It looks like you are turning it up and down, but the sound doesnt change at all. the same firestick worked for my brother on his tv. I just have it hooked up to my television through the hdmi . Did i miss something when hooking it up? i am very illiterate when it comes to tech stuff so please help! I have looked through the settings and cant find seem to find anything related to this.
hopefully this makes sense to someone here and they can help me.
thanks.