Secure REST API with no UI client appliction

My application is a simple spring boot that contains multiple REST api, when invoked, it returns json data. This spring application has no UI on top. The consumers of the application are corporate employee and “services”(non-human, ex: scripts, programs), no UI client application, Corporate employee are all in a LDAP.

My goal is to secure the application so that 1. All authorized corporate employee can access the endpoint while logged in the corporate network SSO. 2. For non-human type of access, they either register their application and we grant them access, or in some other way.

How would I achieve this sort of authentication with OIDC from Okta ?

Thank you.