"Unable to boot ApiServiceProvider, configure an API domain or prefix" with API_PREFIX defined

解决方案：

I had the same problem when using a boilerplate template from
https://github.com/francescomalatesta/laravel-api-boilerplate-jwt

Resolved it by updating my config/api.php file, changing line 60 from
'prefix' => env('API_PREFIX', null),

to
'prefix' => env('API_PREFIX', 'api'),

来源网址：https://github.com/dingo/api/issues/1074