Programming an all key lost on a 2020 explorer smart keys using autel im608, while alarm activated 

You cant do that in an all keys lost situation unfortunately, because the alarm will be activated and the theft deterent system won’t let you. If you were adding a key, that would be a different scenario

Im using 608 and thats the VCI so you can get connection, between the Autel and the vehicle.

You need to disconnect the positive, thats what keeps the charge rolling,