Customize permission message

I have been trying to publish my app on AppStore, but received following message.
Looks like I have to customize permission message to elaborate on why do I need to use camera, I can’t find a way to do this, can anyone help?

Guideline 5.1.1 - Legal - Privacy - Data Collection and Storage

We noticed that your app requests the user’s consent to access their camera but does not clarify the use of this feature in the permission modal alert.