How to use Password in Vue part of Laravel?

Question

Laravel

There is a laravel project with built-in vue
Laravel - as a backend, vue - as a front
Everything that goes to site.com/api - goes to laravel
Everything that site.com/* - goes to vue
How to set passport authorization correctly?
Not to store the client_secret on the front, it's a so-so idea
And with the acceptance of the code, I don't understand how laravel should turn to itself for converting the code into a token
And in general, as I understand it, all these options will request all rights on the side of laravel, but after all vue this is this project .. That is, the site will say that the user must approve the same site rights ...
I’m somehow confused about this, it seems to me that passport is generally superfluous here, because in fact vue and laravel are the same thing, why is there a binding to any client_id, etc.
Maybe there is some simpler way to authorize a user?