MegaApiClient | Net library to access http //mega.co.nz / http | Form library

I want to implement a simple way for a user to upload a save file (a really simple json file with no personal information) to their cloud account. The main problem is that dropbox, google drive etc... don't work with simple username and password, they need OAuth 2, and a browser for log in. But it's not easy to implement that in a Unity game, and it require that I set up a secret API key connected to my account (with limited put and get possible without pay). I want to be able to use the final user account to upload 1 single json file to the user account, and be able to download it from another device (that's the only reason why I want to be able to log in... without log in I can use something like htput, jsonblob or myjson... but if I want the user to be able to get their save in another device I would need that they copy a really long and not easy keyurl generated by those services).

I saw that with MegaApiClient it should be possible. I imported it into Unity as a native Plugin and I was able to use it in my code.

Problem is that I cannot Login because I get an error:

TlsException: Invalid certificate received from server

the code I use it the one in the example:

I'm trying to implement a multiple download function, that would fire and download like 10 files at the same time.

I implemented the IProgress interface too to let me know what's the progress for that.

What I need now is a simple counter inside each of them to say: this is download #1, this is download #2, etc..

I can't do a normal counter since they may all run at the same time and update the counter before me using/storing the value, causing me to have a wrong value or the same value for many of them.

I've looked into the Interlocked class, but I'm just not able to find a suitable implementation for that, that would store a specific number for a each async dynamic function that is triggered.

I'm using the number to store the progress in an array, so I'll just call like:

i am new in C# and this is the first time to me to use this API

i am trying to upload file to me mega Account by C# App

and i succeed in upload but without any progress bar

and the API has this method "UploadFileAsync" but i cant understand every parameter in this method

this is from Object browser in VS

IMegaApiClient.UploadFileAsync(string, CG.Web.MegaApiClient.INode, System.IProgress, System.Threading.CancellationToken?)

System.Threading.Tasks.Task UploadFileAsync(string filename, CG.Web.MegaApiClient.INode parent, System.IProgress progress, [System.Threading.CancellationToken? cancellationToken = null]) Member of CG.Web.MegaApiClient.IMegaApiClient

i know filename and INode parent but what should i write in "System.IProgress progress" and cancellationToken