This is a CAPTCHA generator based on .Net Core and completely loose coupled generator and repositories. There is 3 types of generators (classes that create an image that consists captcha) and 2 repositories (the way you store captcha for later validation) implemented (in memory and Redis).
For this purpose you should create a class that inherites from "ICaptchaGenerator" interface and add the new class to appsettings json file in "GeneratorType".
Repositories used for storing generated captcha and validating it. For this purpose you should create a class that inherites from "ICaptchaRepository" interface and add the new class to appsettings json file in "RepositoryType".