Custom Token Authentication with Craft 3 Login Form I am building token auth system in Craft 3.
https://docs.craftcms.com/v3/dev/examples/login-form.html
I used this Login Form.

Now I am going to create my own token and save it in user profile.

First problem is to link this Form Submit Action to my custom action.
I can not find the controller linked to this action.

How can I customize my login system? Where can I find the controller for the built-in login form logic?
The submit action is the actionInput input {{ actionInput('users/login') }}.
This will call the login method of the src/controllers/UsersController and perform the action.

You may also take a look at User Element &amp; Events where you can listen on various user events like EVENT_BEFORE_VALIDATE, EVENT_BEFORE_AUTHENTICATE etc.