How to upload a file to a Shrine endpoint from another app?

Hello, I’m new to Shrine,

I’m trying to upload a file (audio file, a couple dozen MB) from a react-native app, to a different rails app that uses Shrine. Basically reading the file from the phone’s filesystem, and sending it to a rails app with an Shrine upload endpoint. Is this possible? How would I go about doing this?

I can’t seem to find any examples where there’s no assumption that the front and backend are the same rails app.

thank you,