How do I generate an access token for an Okta service account?

I have a service that authenticates using Okta's verify token endpoint. Currently, this service is only callable by real people who login through the SSO flow. I want to allow other services to interact with this service, but they need an Okta token to do so.

I looked into Okta service accounts and my understanding is they're not different from a regular user. I also understand I am able to create them by manually creating a user.

My question is, what do I need to do after creating the user? How do I exchange the credentials for an access token that I can use to call the service? Everything that I've seen so far requires them to go through the SSO flow, which isn't possible in an automation.