The tutorial from RapidAPI provides a detailed guide on integrating the Twitter API with C# (.NET) in four steps, which include obtaining Twitter API key credentials, connecting to the Twitter API via RapidAPI, selecting "C# (.NET)" from the SDK dropdown, and testing Twitter API endpoints such as retweet, retweetEdit, search, and tweet. The process begins with acquiring Twitter API credentials by creating an application on Twitter’s developer portal, followed by logging into RapidAPI, filling out necessary information, and choosing the appropriate SDK for code generation. Each endpoint requires specific fields, such as tweet IDs and access tokens, to execute actions like retweeting or posting tweets, with code snippets provided to illustrate the implementation. The tutorial emphasizes the ease of testing API endpoints and encourages exploring additional related APIs for enhanced functionality.