getting the contents of a file

I have uploaded a file to Wix for short/medium term use but for the long term I want to store it in a 3rd party storage mechanism. The problem is that the storage mechanism doesn’t take a filename, it requires a buffer with the contents of the file in it (binary data). How do I get a buffer with the contents of a file that I have uploaded to Wix?

Did you find a solution for this. I am in the same boat.