Facing issue from a long time

I created an okta developer account, and now i am trying to use it to secure my spring boot application , but i am facing issue that is ironmentPostProcessorApplicationListener : Your Okta Issuer URL is missing.
what should i do now?
My config is
issuer: https://dev-xxxxxxxx.okta.com/oauth2/default
audience: api://default
client-id: 0oaa8m6n41SqRZxxxxxx
client-secret: 661WlEsEprQw6qHRQwxIeKFPv7m265xxxxxxxxxx
scopes: openid,profile,email,offline_access