The initial token is always manual
If using code flow you’ll get a token and a refresh token
You can use the refresh token to get a new token.
But if the refresh token becomes invalid you’ll need to manually provide a token/refresh token pair
how can the refresh token can get invalid ?
Various reasons
- it expires
- it was revoked
- user changed password
- user revoked link between them and clientID
are just a few possible reasons off the top of my head
i think the first two are the criticle one. Because its my account.Do you know whats the usal time the refresh token expires ?
at time of writing Tiwtch refresh tokens do not have a published expiration.
But oAuth tokens/refresh tokens in general do have expirations
ok thanks 
so best way is to refresh the tokens on a weekly schedule
No.
If you are using a code flow set of keys the access token expires after around 4 hours.
But for a chat bot to send messages the token only needs to be valid when the bot connects to chat. So I tend to refresh then, but my bots need valid tokens to run moderator actions so I refresh at boot and when the token expires
However if you are using the extension chat API you’ll likely need a fresh JWT every call since you shouldn’t make a JWT with am assive expiration, I tend to use 4 (up to 60) seconds when I generate a JWT and discard it after use.
I decided to use the irc. I refresh the token before every message right now which works fine.