In the first step „General“ just enter a random name and choose WordPress as platform.
In next step enter the URL of your WordPress site (just the URL to your front page/home).
To secure the API endpoints and only you are able to access your data, you have to enter authentication credentials.
In last step enter the username you are also using to log into your WordPress site.
Go to the Fancy Product Designer Settings/General tab and scroll down to the REST API section. Here you can set a custom password for the authentication.
After you entered all information, you will be redirected to the website settings page. Here you can test the communication. Just click the button and you will receive feedback about any problems.