There are no restrictions on how you create the client code that you use to communicate with the API; you can write your own client, or have one generated from the API specification.
The API has a published swagger specification here which can be used to generate a client.
As a convenience, we have provided the button below which will generate client code. This uses the online generator at openapi-generator.tech with the default options. You are free to use this, use another client generator, or roll your own client.