Federation Identity Management From Spring oauth2

Dear Team

I am trying to use okta as an idp from a spring oauth2 app: my settings look like this

in the yml application :
spring:
security:
oauth2:
client:
registration:
okta-idp:
provider: okta
client-id: {}
client-secret:{}
scope: openid
client-name: Sign in with Okta
github-idp:
provider: github
client-id: ${GITHUB_CLIENT_ID:github-client-id}
client-secret: ${GITHUB_CLIENT_SECRET:github-client-secret}
scope: user:email, read:user
client-name: Sign in with GitHub
provider:
okta:
user-name-attribute: email
github:
user-name-attribute: login

and on the client it is set like this :
https://dev-xxxxx.okta.com/oauth2/v1/authorize?idp=xxxxxxx

i removed sensitive info of course.
My question is how to access okta as idp as the url is wrong. it work for google and github but not for okta, may you tell me how to setup the correct idp url for okta without saml.
thanks in advance ,

regards
david