How do I temporarily allow Android to install app from play store?

I have installed BitDefender on 5 devices and set all of them up in a parental control group. I now need to allow a user to install an app from the Play Store but the device is asking for a password. I don't want to give him the password, or at least I want to be able to change the password temporarily and then reinstate the original password but can't figure out how to do it.