How to register new user with myopenhab.org using rest api

I have to register new user with myopenhab.org using rest api, I have Client secret key as well as uuid with me. How can i do it as it will be done on myopenhab.org website using rest api

There is not REST API for myopenhab.org to my knowledge. There certainly isn’t a published one.

You have to register new users through the myopenhab.org UI after logging in with your main user.