How to get android file full path name?

on the android, i using some third part lib, it need full file name to call some function. is there any function or any way convert a relative path to full name? ( like from “…/…/…/Save/” to “/storage/emulated/0/UE4Game/xxx/xxx/Save/” )

Explre FPaths class it has ton of path related functions:

Since you work with 3rd party libries remeber that add * operator before string varable will return char array which is more friendly with external libs