Disable cell phone sounds completely?

The title says it already I want to deactivate all possible sounds on my Samsung A51 that is very easy with the "do not disturb" button but on my new Huawei Honor 20 pro there's no longer a button or it does not work.

Is there a way to mute the device? (So that even if you accidentally touch the side buttons, the sound does not come on again)

You can remove the speaker, but then you can no longer make calls.

Does the do not disturb mode not work?

https://consumer.huawei.com/...e00747937/