Node.js Rest API For mobile application. Need help with the authorization module?

Question

Mobile development

Good day to all.
Faced such task. I'm writing a Rest API in Node.js for a mobile application (messenger). I have never written a backend for mobile applications before, and then the question arose: What is the best way to make an authorization module? I read a lot of information about oAuth2 and so on. But for me, the question still remains unclear, how does all this authentication happen in mobile applications and how best to implement it? Since authorization in mobile applications is slightly different from authorization in web applications. It remains unclear to me the fact of how a one-time authorization occurs, and how the same authorization is then updated (i.e. the user logged into the mobile application for the first time, registered, logged in, and then even if he left the application and enters it only a month later he will not need a new login and password for authorization, but simply authorization will occur instantly when entering the application). What is needed for this? Is it done the same way via JWT? Those. specifying the question, what architecture of the authentication module should be, and what should I use to write this architecture on the server side? If possible, please answer in detail. Thank you all in advance)