uploading files (not apps)

I'm writing a small app for my bangle to allow scrolling through a list of items (e.g. navigation directions, but this could apply to shopping lists as well).
For that I am looking for a way to upload the directions file (or shopping list).
Is that possible?

Below is a simplified example, but that one uses a static array.
I know how to read the info from a file, but it is not clear to me what the best way is to upload the file.

(BTW: I also considered a small generator that creates a dedicated app, but I feel that is more cumbersome).

Thanks, Frans

PS: and pardon me if this is the wrong forum, but I felt none of the forums was really applicable.

const vals = [
  "",
  "1st left", 
  "2nd right",
  "cross railroad",
  "stop at #17",
  ""
];


let ix = 1;

function draw()
{
  g.clear();
  g.setFontVector(20);
  //g.setColor(passivColor);
  g.setFontAlign(0, -1, 0);
  g.drawString(vals[ix-1], 120, 0);
  g.drawString(vals[ix+1], 120, 200);
  g.setFontVector(30);
  g.drawString(vals[ix], 120, 100);
}

function next() {
  if (ix < vals.length - 2) ix = ix + 1;
  draw();
}
function prev() {
  if (ix > 1)  ix = ix - 1;
  draw();
}

setWatch(next, BTN5, { repeat: true });
setWatch(prev, BTN4, { repeat: true });

draw();