Can I use an Okta access token to gain access to another Oauth2 app ?

Hi everyone,
I am new member Okta.
Currently, My team will use Okta to login, but when integrated with Okta it will have an impact on existing oauth-using systems.
How to the access token of Okta can validate and access to my Oauth2 and generate a new access token from my Oauth2 and use it with currently flow.

I’m not sure I understand your question? Are you asking about how to complete token validation and token refreshes?