You can ensure the privacy of your users' information in a few possible ways.
First, you can use the private view APIs available for both iOS and Android. On iOS, this will cause a black box to appear over specific fields set as private. On Android, it will show a black box over the entire activity due to this being an OS API.
Secondly, your users will have the option to blur out sensitive information in the captured screenshot as displayed in the image below.