How do I make OAuth client token permanent?

My ultimate goal is to keep the polling service running without the need of manual intervention for very long time.
I am not using the npm package because it doesn’t have typings, but the service is pure TypeScript.

Is it possible to have a client token that never expires? If not, how should I code it to refresh the token automatically? New to OAuth2 so I am not expert enough to know how should I do it.

The creator access token should be long lived and should act like an api key for most purposes. However you should still refresh it every once a while, maybe 2-3 months etc.