how I can achieve this since we have used your api for this entire process.

Thanks for your answer, but I realy need to use the back camera of any phone or tablet (I will use android devices).
The scenario I have is the following:
People who are going to attend an event that we organize will be registered at the event and as part of the process they register their face using the enrollment process.
On the day of the event I want to use tablets, which will be given to the security team, so they can validate that the people coming to the event are the ones who completed the registration process. I wouldn't like them to have to turn their phone or tablet around to read the face of the person who enters.
This is why it is of utmost importance that the face reading is carried out with the rear camera.
Please I need you to tell me how I can achieve this since we have used your api for this entire process.