Error"Unable to authorize access because the client configuration is invalid: invalid_request"

I'm trying to get the Authorization code to generate Access token, the following is the URL that I'm using

https://secure.echosign.com/public/oauth?redirect_uri=https://oauth.pstmn.io/v1/callback&response_type=code&client_id={clientid}=agreement_read:account+agreement_write:account+agreement_send:account+widget_read:account+widget_write:account+workflow_read:account

When I run the following URL in the browser it is throwing the following error -

Unable to authorize access because the client configuration is invalid: invalid_request

Can anyone help me?

Thank you in advance.