Getting Started with Patreon API

Hi,
I have gotten the clientid and clientsecret of the application.

var clientid = ‘sample id’
var redirecturl =‘http://localhost:3000

I have set up the format of the url to use oauth as:
var url = ‘https://www.patreon.com/oauth2/authorize?response_type=code&client_id=’ + clientid +’&redirect_uri=’ + redirecturl +’&scope=&state=’

After I open the above link. I do not get to any page that allows me to login with my patreon account.
What I get is a redirection to the redirect url with some parameters passed into it:
http://localhost:3000/?error=invalid_scope&state=<optional+string>

What does this mean and what am I doing wrong?

I would like to give Patreon members who have contributed to the creator access to the website.