Maybe you just have to read this website :
https://www.codewall.co.uk/laravel-route-not-defined-checklist/
Use Postman and set the Header `Accept: application/json` otherwise Laravel
Passport would never know it's an API client and thus redirect to a /login
page for the web.
You're trying to redirect to a named route whose name is login, but you have
no routes with that name:
Route::post('login', [ 'as' => 'login', 'uses' => 'LoginController@do']);
The 'as' portion of the second parameter defines the name of the route. The
first string parameter defines its route.