My connected device through bluetooth is a laptop named AVICK. When I tap the more option button in the 2nd photo there is an option use for call. How can I use this feature?

There are some in built apps which I have never used. These apps are just taking my phones space and can't be disabled. I have Galaxy J7 Nxt phone with 16 GB of space. I often face low space in my phone. Then some features aren't available. And then ...

Sir sometimes we need the flashlight during a video call but it can't be turned on while video calling

Can I use my earphone button as my camera button on my J7 Nxt?Actually when I press the earphone button then my Google Assistant pops up.Can I turn off this service?