How to copy chart files onto an Android phone?

[GHA]

Confirming that Micro sd cards come with an adapter which you plug them into which then plugs into the sd card slot on your PC.
You can then put as many as you want on your android micro sd card.
Only problem is that in my experience is that an ap like open cpn will not read it from within the android system
The only files on an sd card that are readable are pic and movie files.

Works fine with a win10 laptop -> Xperia tablet with kap files in opencpn.