File Copy Transfers Using ES FILE EXPLORER - Demo on Mi Redmi 5 Phone on the latest MIUI 9.6 Stable version.
Here in this test using Mi Redmi 5 (MIUI 9.6), there was no need to enable DOCUMENTS app under INSTALLED APPS. In fact, DOCUMENTS app was not found at "SETTINGS - INSTALLED APPS".
In the previous video (link below), there was a need to enable "DOCUMENTS" under "SETTINGS - INSTALLED APPS" while using ES FILE EXPLORER to transfer files.
Resolved -File transfer issue to SD-CARD on MI Phones using ES FILE EXPLORER https://www.youtube.com/watch?v=q0w3kZm3XA4
Refer previous blog post: Resolved: Unable to transfer or copy files to SD Card issue on MI phone using ES File explorer
How to find and enable DOCUMENTS in Mi Phones
https://www.youtube.com/watch?v=EBmoNL1mpNU