Basic salesforce integration with yii2 httpclient

Hi guys, I’d need to integrate yii2 with salesforce api. I have 2 main questions:
1- how to create the auth system? I have static params to connect to the external api endpoint and get the jwt token.
2- after getting the jwt, i should use session to store the jwt and then pass it as bearer on every request?

The code must do the login autamatically, because the jwt expires after 2 days. Give me pls some advice. Thanks.