Yes, it is here:
File Upload - Backendless REST API Documentation
At the moment, I don’t have time for video. But I can offer screen shots for appgyver users that want to upload and retrieve images. Example:
UI Example
Image Upload Logic
Button Logic
Page Logic
Backendless DB
You will need one app variable.
And you will need one page variable.
App variable is to store image static url and to set image path from pick images from library.
Page variable stores base 64 + prefix
To retrieve image, run test, store response schema, create data variable, then bind the image to the imageUrl.