How to let Emacs open and display a file in directory /storage/emulated/0/?

I am using Samsung Galaxy S10+ on Android 12. From F-Droid, I have downloaded and installed Emacs. It can run directly on Android, not via Termux. In the internal storage of my phone, I have created a file /storage/emulated/0/WE_test01.txt. By using the X-plore text editor, I have written 2 lines:

asd
123

Then, this file is to be opened by Emacs. I hit on the Emacs icon and typed C-x C-f, and in the bottom line /storage/emulated/0/WE_test01.txt. The response of Emacs is > File is not readable What have I done wrong?