Android ransomware removal not working

Hello,
My Android tablet has randomware installed (the typical uk police/fbi lock screen). I’ve downloaded avast ransomware removal via my pc onto the tablet.

when I select the item in my notification tray nothing happens, the police lock screen still appears.

Am I doing something wrong or has this evolved and avast no longer works?

Thanks.

Try posting in this forum section Avast Mobile Products >> https://forum.avast.com/index.php?board=66.0

one option to try if all other fail, factory resett your tab