switching paid secureline subscription from iPhone to android device?

I purchased the 1 year subscription of avast secureline on my iPhone a few months ago. I now have an android phone and want to use the same subcription on my new phone. When I installed the app on the new phone it asked if I hade a license already, I selected yes, then it takes me to the home screen and says I can have up to 5 devices registered under one license. How do I get that license I purchased on my iPhone onto my android without having to pay again?