Redmii Note 4
how to get App Lock in your mobile phone
step 1. go to security
step2.
go to app lock
step 3.
click on app lock
you can see thew blue light is not turn on it means lock is not set
step4.
there is blue light is shown that means it is on.
your app is secure and to unlock you can use your finger print and some password
thanks for more detail connected with us.