how can i turn off the new facebook app sounds

[Windows Central Question]

FB stopped working properly on my phone yesterday so I reinstalled it today and it is obviously a new version, more like the Android and IOS versions which is great - except it has those annoying noises every time you do anything on it! It looks like on the other devices you can turn them off but I can't find a 'sounds' option in the app to do the same on my Windows 10 phone. I've tried everything else in the normal notifications. Help!