Save and Save as function in Android app

Hello, I use your Android app (F-Droid).
For the most part, I am very satisfied, but I have the following problem:
When I open an `*.md` file and then click on _Save_, I have to enter a new file name. It is not possible to overwrite the original file.
Would it be possible to implement the _Save_ function as overwriting the original file and rename the existing _Save_ function to _Save as_?