How to engage active track

[Mantrain]

Can someone explain how to bring up the active track fx's on the M3? I have all my firmwares up to date but I cannot locate the function in the FlyApp.
Thanks!

 

[Campin123]

With your finger, draw a box around the subject and the menu will pop up.

 

[Campin123]

With your finger, draw a box around the subject and the menu will pop up.

The drone must be in the air

 

[Mantrain]

With your finger, draw a box around the subject and the menu will pop up.

well I tried I was only getting a yellow box and nothing would happen.