Restrict API users sign in from Web Admin Portal

My Laravel application has an API(students) and a web portal(admins). students register via API. Admin users are generated by a super admin. They login via the admin portal. App\User model has been used to facilitate both types of users with the Spatie Laravel Roles and Permissions.

'guards' => [
    'web' => [
        'driver' => 'session',
        'provider' => 'users',
    ],

    'api' => [
        'driver' => 'token',
        'provider' => 'users',
        'hash' => false,
    ],
]

The problem is that the users who registered from the API can login via Web portal. But after login they cannot do anything because the web routes are having a role based middleware.

// web.php routes

Auth::routes(['register' => false]);

Route::group(['middleware' => ['role:admin']], function () {
    Route::resource('classes', 'WEB\ClassController');
    Route::resource('teachers', 'WEB\TeacherController');
});

// api.php routes

Route::post('register', 'API\RegisterController@register');
Route::post('login', 'API\LoginController@login');

Route::group(['middleware' => 'auth:sanctum'], function () {
    Route::resource('papers', 'API\PaperController');
    Route::resource('marks', 'API\MarkController');
});

What can I do to handle this situation?