App rejected - add parental gate

[William de Smet]

Hi there,

An app update was rejected due to the fact I ticked the ‘Kids category’ in the initial version of the app. In the app they can share an image outside the app. The current quidelines say I have to add a parental gate now. 
Is there anyone who has an example on how to do this?
https://developer.apple.com/app-store/parental-gates/

Greetings, 

William