Fileupload button don't work in apk

[mimatek]

Hi, I have a problem with the container of my unigui application. 
I have to indicate that I consider myself more a management and analysis programmer than a specialist with javascript or HTML5 
or other web environments. I have an unigui application that I want to contain (like others that I read in the forum) in a 'native' application, 
in my case, for android. The application is basically a webbrowser from which I call the unigui application. 
I've tried it in android studio, with b4a and with Delphi 10 3.2 Rio and the problem is that everything works fine except for 
the fileupload button, which does nothing. The question is: what permissions do I need to activate, other than READ_EXTERNAL_STORAGE / 
WRITE_EXTERNAL_STORAGE and enable javascript in webbrowser, in android container, so that unigui works completely? 
For example, the fileupload button ... Thanks in advance.

[Grupo Datasoft Ltda.]

Hola mimatek, alguna vez lograste resolver este problema?