I am not an expert. I am only a senior developer with about 23 years experience. That does not make me or anyone else here an expert. In fact; most of us here are still learning tricks bits and bobs from each other.
The language Instagram provide examples for is not limited to the language you can use. Like any API, (and I am in the process of building a huge one.) They are not restricted by a given language. They all take post/put and get requests. The only difference is you need to work out how to do post put get and delete requests etc in C# and send those requests to their servers API. (Again; reminding you as Skydiver pointed out my previous statement, that their API is a display API and can't be used for post requests.)