Why PHP Artisan Tinker kept showing null?

┌──[root@jdoe]──[/home/jdoe/jdoe] 
└── cat .env | grep APP_URL
APP_URL=https://www.jdoe.com                                                                                                                     
┌──[root@jdoe]──[/home/jdoe/jdoe] 
└── php artisan tinker
Psy Shell v0.10.2 (PHP 7.3.11-0ubuntu0.19.10.3 — cli) by Justin Hileman
>>> env('APP_URL')
=> null
>>> env('APP_URL');
=> null
>>> 

I support to see https://www.jdoe.com

Someone want to explain this ?

via Chebli Mohamed