I subscribe to Readly which allows me to read 1,500+ magazines, with new issues every month.

I can't see anything on their site to answer this. It is probably a legal question, but can I ask how to download those magazines I order to read them offline?

Presumably, when I open one for reading, it is cached somewhere on my device (Mainly Windows laptop & occasionally Android), Is it on-topic to ask where to find those cached magazines and copy them for offline reading?