How to access file from C# code on android Unity app?

Question

Android

Hello!
I'm making an android app with Unity. In the C# code, there is a read of an external file that was stored in Assets/Data. Everything was easy until I built and opened the project on an android phone. Those lines in the application that should have been read from the file are empty.
I have been looking for an answer for several days, but, most likely due to the fact that I am too green in my yunk, I cannot understand anything.
How can I make it so that the apk file already had the txt files I needed, which I could read in the code?

Answer 1

https://docs.unity3d.com/Manual/StreamingAssets.html